Answer: The theoretical yield of 4-nitrochalcone is, [tex]2.13\times 10^2[/tex]
Explanation : Given,
Volume of acetophenone = 135 microliters = 135 × 10⁻⁶ L = 0.135 mL
conversion used : (1 microliter = 10⁻⁶ L) and (1 L = 1000 mL)
Density of acetophenone = 1.03 g/mL
Mass of acetophenone = Density × Volume = 1.03 g/mL × 0.135 mL = 0.139 g
Mass of 4-nitrobenzaldehyde = 127 mg = 0.127 g
Conversion used : (1 mg = 0.001 g)
First we have to calculate the moles of acetophenone and 4-nitrobenzaldehyde
[tex]\text{Moles of acetophenone}=\frac{\text{Given mass acetophenone}}{\text{Molar mass acetophenone}}[/tex]
[tex]\text{Moles of acetophenone}=\frac{0.139g}{120.15g/mol}=0.00116mol[/tex]
and,
[tex]\text{Moles of 4-nitrobenzaldehyde}=\frac{\text{Given mass 4-nitrobenzaldehyde}}{\text{Molar mass 4-nitrobenzaldehyde}}[/tex]
[tex]\text{Moles of 4-nitrobenzaldehyde}=\frac{0.127g}{151.12g/mol}=0.000840mol[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical equation is:
[tex]C_8H_8O+C_7H_5NO_3\rightarrow C_{15}H_{11}NO_3[/tex]
From the balanced reaction we conclude that
As, 1 mole of 4-nitrobenzaldehyde react with 1 mole of acetophenone
So, 0.000840 mole of 4-nitrobenzaldehyde react with 0.000840 mole of acetophenone
From this we conclude that, acetophenone is an excess reagent because the given moles are greater than the required moles and 4-nitrobenzaldehyde is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of 4-nitrochalcone
From the reaction, we conclude that
As, 1 mole of 4-nitrobenzaldehyde react to give 1 mole of 4-nitrochalcone
So, 0.000840 mole of 4-nitrobenzaldehyde react to give 0.000840 mole of 4-nitrochalcone
Now we have to calculate the mass of 4-nitrochalcone
[tex]\text{ Mass of 4-nitrochalcone}=\text{ Moles of 4-nitrochalcone}\times \text{ Molar mass of 4-nitrochalcone}[/tex]
Molar mass of 4-nitrochalcone = 253.25 g/mole
[tex]\text{ Mass of 4-nitrochalcone}=(0.000840moles)\times (253.25g/mole)=0.21273g=212.73mg=2.13\times 10^2mg[/tex]
(1 g = 1000 g)
Therefore, the theoretical yield of 4-nitrochalcone is, [tex]2.13\times 10^2mg[/tex]
A marine biologist is preparing a deep-sea submersible for a dive. The sub stores breathing air under high pressure in a spherical air tank that measures 74.0 wide. The biologist estimates she will need of air for the dive. Calculate the pressure to which this volume of air must be compressed in order to fit into the air tank. Write your answer in atmospheres. Round your answer to significant digits.
Complete Question
A marine biologist is preparing a deep-sea submersible for a dive. The sub stores breathing air under high pressure in a spherical air tank that measures 74.0 wide. The biologist estimates she will need 2600 L of air for the dive. Calculate the pressure to which this volume of air must be compressed in order to fit into the air tank. Write your answer in atmospheres. Round your answer to significant digits.
Answer:
The pressure required is [tex]P_2= 12.2 \ atm[/tex]
Explanation:
Generally the volume of a sphere is mathematically denoted as
[tex]V_s = \frac{4}{3} * \pi r^3[/tex]
Substituting [tex]r = \frac{d}{2} = \frac{74}{2} = 37cm[/tex]
[tex]V_s = \frac{4}{3} * 3.42 * (37)^2[/tex]
[tex]V_s = 2.121746 *10^5 cm^3[/tex]
Converting to Liters
[tex]V_s = \frac{2.121746 *10^5}{1000}[/tex]
[tex]V_s= 212.1746L[/tex]
Assume that the pressure at which the air is given to the diver is 1 atm when the air was occupying a volume of 2600L
So
From Charles law
[tex]P_1V_1 = P_2 V_s[/tex]
Substituting [tex]V_1 =2600 L[/tex] , [tex]P_1 = 1 atm[/tex] , [tex]V_s =212.1746L[/tex] , and making [tex]P_2[/tex] the subject we have
[tex]P_2 = \frac{P_1 * V_1}{V_s}[/tex]
[tex]= \frac{1 * 2600}{212.1746}[/tex]
[tex]P_2= 12.2 atm[/tex]
Which words or phrases identify the types of temperate climates? Check all that apply.
humid continental
highland
it is actually science on the subject but it doesn't have that option.
marine west coast
Mediterranean
subarctic
tropical wet-dry
Answer:
Humid Continental
Marine west coast
Mediterranean
subarctic
Explanation:
just did assignment on edge
Marine west coast and Mediterranean are the types of temperate climates, due to the dispersion of precipitation throughout the year, temperate marine climates are typically distinguished by a notable lack of dry season, hence options D and E are correct.
What is temperate climates?Temperate climates are regions with moderate annual or seasonal rainfall, intermittent drought, mild to warm summers, and cool to cold winters.
Humid subtropical, marine west coast, Mediterranean are the phrases that clearly identified with temperate marine climates.
Geographically speaking, the moderate climates of Earth are found in the middle latitudes, which are halfway between the tropics and the poles.
Therefore, options D and E are correct.
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Think about what you've learned about how particle motion is related to temperature.
Select all of the statements that are true.
1. The average kinetic energy of the particles in a substance determines the
substance's temperature.
2. If the particles in two pure substances have the same average speed, the
substances can have different temperatures.
3. When two substances have the same temperature, all of the particles in
both substances are moving at the same speed.
4. How fast a substance's particles are moving determines how hot or cold
the substance is.
Final answer:
The true statements about particle motion and temperature are that the average kinetic energy of the particles in a substance determines its temperature and that faster moving particles generally result in a higher temperature of the substance.
Explanation:
The relationship between particle motion and temperature is based on the kinetic-molecular theory. According to this theory, temperature is proportional to the average kinetic energy of the particles, such as molecules or atoms, in a substance. Therefore:
The average kinetic energy of the particles in a substance determines the substance's temperature.
If the particles in two pure substances have the same average speed, it does not necessarily mean they have the same temperature, since heavier particles will have more kinetic energy at the same speed, leading to different temperatures.
When two substances have the same temperature, it indicates that the average kinetic energy of the particles in both substances is the same, not that all of the particles are moving at the same speed, because particles have a range of speeds.
The speed of a substance's particles can give an indication of how hot or cold that substance is. Faster moving particles generally mean a higher temperature.
As such, the true statements are 1 and 4. Understanding that temperature is not simply a measure of particle speed, but rather the average kinetic energy involved, clarifies misconceptions about the nature of thermal energy and its measurement.
To make use of an ionic hydrate for storing solar energy, you place 422.0 kg of sodium sulfate decahydrate on your house roof. Assuming complete reaction and 100% efficiency of heat transfer, how much heat (in kJ) is released to your house at night
Complete Question
To make use of an ionic hydrate for storing solar energy, you place 422.0 kg of sodium sulfate decahydrate on your house roof. Assuming complete reaction and 100% efficiency of heat transfer, how much heat (in kJ) is released to your house at night? Note that sodium sulfate decahydrate will transfer 354 kJ/mol.
Answer:
The amount of energy released is [tex]x = 4.63650 *10^5 KJ[/tex]
Explanation:
Number of moles is mathematically represented as
[tex]n =\frac{mass}{Molar\ Mass}[/tex]
substituting [tex]422.0kg = 422 *10^3g[/tex] for mass of sodium sulfate decahydrate([tex]Na_2 SO_4 \cdot 10H_2 O[/tex]), [tex]322.2g/mol[/tex] (This value is a constant )for the molar mass of sodium sulfate decahydrate
[tex]n= \frac{422*10^3}{322.2}[/tex]
[tex]= 1309.7 \ moles[/tex]
From the question we are told that
1 mole of sodium sulfate decahydrate generates [tex]354KJ[/tex] of energy
So 1309.7 mole would generate x
Now stating the relation mathematically
1 mol → 354KJ
1309.7 mol → x
=> [tex]x = 4.63650 *10^5 KJ[/tex]
The formation of ClF (chlorine monofluoride) from its elements has an equilibrium constant of 22.3 at room temperature. Which of the following statements is correct if chlorine gas and fluorine gas are mixed at room temperature?
The reaction will form products until equilibrium is established
Products are quickly formed
A negligible amound of ClF is formed
Products are slowly formed
Answer:
A the reaction will form
Explanation:
For each reaction, calculate how many moles of the barium product you will produce using stoichiometry and the balanced reactions.since there are two reactants, calculate the moles of product using each reactant, and then use the number of moles which is less) this comes from the limiting reactant).
Moles of Ba(NH2SO3)2.
Answer:
Explanation:
given that
mass of Ba(NO3)2 = 1.40g
mass of NH2SO3H = 2.50 g
1)to determine the mole of Ba(NO3)2
2) to determine the mass of all three product formed in the reaction
reaction
Ba(NO3)2 + 2NH2SO3H → Ba(NH2SO3)2 + 2HNO3
Solution
we calculate the molar mass of each species by using their atomic masses
BA = 137.33g/mol
N = 14g/mol
O= 16g/mol
H = 1g/mol
S = 32g/mol
calculation
Ba(NO3)2 = Ba + 2N + 6O
= 137.33 + 2X 14 + 6 X 16
= 261.33g/mol
NH2SO3H = N + 3H + S+ 3O
=14 + 3X1 + 32 + 3X 16
= 97g/mol
Ba(NH2SO3)2 = Ba + 2N + 4H +2S +6O
= 137.33 + 2 X 14 + 4 X1 + 2X32 + 6 X 16
= 329.33g/mol
HNO3 = H + n + 3O
= 1 + 14 + 3 X 16
= 63g/mol
A mixture of krypton and hydrogen gases, at a total pressure of 692 mm Hg, contains 20.9 grams of krypton and 0.133 grams of hydrogen. What is the partial pressure of each gas in the mixture?
Answer:
Partial pressure Kr → 546.1 mmHg
Partial pressure H₂ → 145.9 mmHg
Explanation:
To determine the partial pressure of each gas in the mixture we apply the mole fraction concept.
Mole fraction → Moles of gas / Total gas = Partial pressure / Total pressure
In this mixture: Partial pressure Kr + partial pressure H₂ = 692 mmHg
We determine the moles of each:
20.9 g / 83.80 g/mol = 0.249 moles Kr
0.133 g / 2 g/mol = 0.0665 moles H₂
Total moles: 0.249 moles Kr + 0.0665 moles H₂ = 0.3155 moles
Mole fraction Kr → 0.249 mol / 0.3155 mol = 0.789
Partial pressure Kr → 0.789 . 692mmHg = 546.1 mmHg
Partial pressure H₂ → 692mmHg - 546.1 mmHg = 145.9 mmHg
NEED HELP ASAP!!! I WILL GIVE 100 POINTS!!!
Describe the investigations from the readings that are being conducted to learn more about how much water flows in major rivers around the world. Explain why the researchers think that data from the rivers is related to climate change. Cite facts from the texts in your response.
Need to make at least a 3 paragraph essay. 4 sentences in each paragraph pls.
Heres the article:
BOULDER, Colorado. A new study has revealed that the flow of water from Earth's largest rivers has declined over the past 50 years, due primarily to climate change.
A team of researchers at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, discovered the reduction in water flow after analyzing the discharge from 925 major rivers around the world between 1948 and 2004. Among Earth's dwindling rivers are Asia's Changjiang (or Yangtze), Mekong, Ganges, Irrawaddy, Amur, and Xijiang. Also included are Africa's Congo and Niger rivers and South America's Amazon River. North America's Mackenzie and Columbia rivers are also affected.
Researchers assessed the overall effect of the shrinking rivers on the various oceans into which they drain. They used cubic kilometers as their unit of measurement. The researchers found that the overall trend over the years was a decrease in the rates of discharge. Over the past half-century, they found, the yearly amount of fresh water flowing into the Indian Ocean fell by about 3 percent, or 140 cubic kilometers. The annual river discharge into the Pacific Ocean dropped about 6 percent, or 526 cubic kilometers. Researchers noted that in terms of quantity, the decline in streamflow into the Pacific is equal to shutting off the Mississippi River.
Meanwhile, researchers discovered only a negligible variation in the annual river flow into the Atlantic Ocean. There, decreases in the Amazon River were offset by increases in South America's Parana River and our own Mississippi River. Due to increased rainfall, the Mississippi saw an increase in its flow of more than 22 percent over the period studied.
Aiguo Dai was the study's lead researcher. According to Dai, the only ocean showing a significant increase in the freshwater flow it received was the Arctic Ocean. There, annual river streamflow rose about 10 percent, or 460 cubic kilometers.
According to Dai, the change in river flows is primarily a result of climate change. Earth's warming temperatures have caused flooding in some regions. Other areas have experienced reduced precipitation and droughts. Droughts place even greater demands on the already shrinking rivers. They increase the need for dams and other diversions of river water for agriculture and industry. For example, decreased precipitation and increased water diversion caused a 14 percent reduction in the flow in the northwestern U.S.'s Columbia River.
"Freshwater resources will likely decline in the coming decades...due to climate changes," Dai said.
In the Arctic, climate change is responsible for accelerating the melting of snow and ice. This accounts for the increased discharge into the Arctic Ocean.
"[Rapidly] disappearing mountain glaciers in [higher latitudes] will make matters worse," said Dai.
In some regions, the effects of climate change on Earth's rivers are compounded by regularly occurring weather phenomena. Take the El Niño phenomenon, for example. An El Niño is a periodic cooling of sea surface waters in the tropical Pacific. Researchers noted that the El Niño phenomenon led to lower flows in the Amazon River and higher ones in the Mississippi River when it was in effect.
Researchers are concerned about the reduction in rivers, particularly the Yellow River in northern China, the Ganges in India, the Niger in West Africa, and the Colorado in the southwestern U.S. These rivers flow through densely populated areas, where water is in greater demand than in areas with smaller populations.
"These changes will have impacts on humans and ecosystems," said Margaret A. Palmer. Palmer is director of the Chesapeake Biological Laboratory of the University of Maryland Center for Environmental Science. "Many of these regions have large populations and drought-stressed ecosystems."
There are other reasons to be concerned about the diminished streamflow. One is that rivers supply oceans with essential nutrients. Another is that changes in streamflows can induce changes in ocean temperatures and salt levels. These changes are known to affect global ocean circulation patterns.
NCAR scientist Kevin Trenberth is concerned about climate change and its effects on rivers—and ultimately humans. "As climate change inevitably continues in coming decades," Trenberth said, "we are likely to see greater impacts on many rivers and water resources that society has come to rely on."
Answer:
In the first paragraph state how climate change is the earth warming. Tell them how the warmer atmosphere has lead to the melting of snow and ice in the arctic and sever droughts in other areas of the world.
In the second paragraph talk about how large rivers are becoming smaller in regards to water volume and that the amount of water discharged into the ocean has also decreased greatly.
In the final paragraph write about how weather phenomena impact global warming. State that El Niño has led to lower floods in some place whereas other areas have experienced an increase in floods. Finally tell the reader how the lower water volumes and discharge leads to a change in the global ocean circulation.
Explanation:
Nitrogen and hydrogen gases are combined at high temperatures and pressures to produce ammonia, NH3. If 101.7 g of N2 are reacted with excess H2, how many moles of NH3 will be formed
Answer:
7.26 moles of NH₃ are formed in this reaction
Explanation:
This is about the reaction for the production of ammonia
1 mol of nitrogen gas reacts to 3 moles of hydrogen in order to produce 2 moles of ammonia.
The equation is: N₂ + 3H₂ → 2NH₃
In the question, we were informed that the excess is the H₂ so the N₂ is limiting reagent. We determine the moles, that has reacted:
101.7 g / 28 g/mol = 3.63 moles
So, If 1 mol of nitrogen gas can produce 2 moles of ammonia
3.63 moles of N₂ must produce ( 2 . 3.63) / 1 = 7.26 moles of NH₃
Answer:
In this reaction, 7.26 moles of NH3 will be formed.
Explanation:
Step 1: Data given
Mass of N2 = 101.7 grams
Molar mass N2 = 28.0 g/mol
H2 is in excess
Molar mass H2 = 2.02 g/mol
Molar mass of NH3 = 17.03 g/mol
Step 2: The balanced equation
N2(g) + 3H2(g) → 2NH3(g)
Step 3: Calculate moles N2
Moles N2 = mass N2/ molar mass N2
Moles N2 = 101.7 grams / 28.0 g/mol
Moles N2 = 3.63 moles
Step 4: Calculate moles NH3
For 1 mol N2 we need 3 moles H2 to produce 2 moles NH3
For 3.63 moles N2 we'll produce2*3.63 = 7.26 moles NH3
In this reaction, 7.26 moles of NH3 will be formed.
The equilibrium for the indicator methyl orange is HC14H14SO3(red) + H2O C14H14SO3−(yellow) + H3O+ The reaction is exothermic.
Explain in words, what happens when this is added to an acidic solution.
Answer:
The solution will turn red.
Explanation:
HC₁₄H₁₄SO₃ + H₂O ⇌ HC₁₄H₁₄SO₃⁻ +H₃O⁺
(red) (yellow)
Methyl orange is a weak acid in which the ionized and unionized forms are distinct colours and are in equilibrium with each other,
At about pH 3.4, the two the forms are present in equal amounts, and the indicator colour is orange.
If you add more acid, you are disturbing the equilibrium.
According to Le Châtelier's Principle, when you apply a stress to a system at equilibrium, it will respond in such a way as to relieve the stress.
The system will try to get rid of the added acid, so the position of equilibrium will move to the left.
More of the unionized molecules will form, so the solution will turn red.
Draw one product structure for the following Diels–Alder reaction. For ONLY the chirality centers with D and C(=O)H groups, specify the stereochemistry via wedge-and-dash bonds. (D is deuterium, an isotope of hydrogen. Include it in your drawing by either double clicking on an atom and typing \"d\" or by choosing D in the bottom row of the atoms menu.)
Answer:
See explaination
Explanation:
We can define the Diels-Alder reaction as a conjugate addition reaction of a conjugated diene to an alkene (the dienophile) to produce a cyclohexene.
Please kindly check attachment for the step by step solution of the given problem.
The Diels–Alder reaction is an organic chemistry reaction involving a cyclic rearrangement of atoms to form a six-membered ring. The product structure from such a reaction should specify stereochemistry with wedge-and-dash notation for the chirality centers involving carbon atoms and Deuterium (D). A wedge implies the bond is positioned towards you, while a dash implies the bond is positioned away from you.
This is a Chemistry problem dealing with the Diels–Alder reaction, a fundamental reaction in organic chemistry, which is a very key method in the synthesis of complex molecules. In essence, the Diels–Alder reaction involves a cyclic rearrangement of atoms rearranging to form a six-membered ring. Let's take a Diels–Alder reaction template where:
two carbon atoms involved in the double bond are labeled as X and Y,
the carbonyl carbon is labeled as Z,
the specific hydrogen atom replaced by Deuterium (D) is labeled as W.
Thus, when a Diels–Alder reaction is performed, the product structure will maintain relative positions. Carbon atoms X and Z will have wedge orientation while Carbon atoms Y and the Deuterium (D) on W will have dash orientation.
Remember, in wedge-and-dash notation, wedge implies the bond is coming up out of the plane (positioned towards you), while dash implies the bond is going back into the plane (positioned away from you).
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A 50.0 mL sample containing Cd^2+ and Mn^2+ was treated with 42.8 mL of 0.0500 M EDTA. Titration of the excess unreacted EDTA required 17.8 mL of 0.0250 M Ca^2+. The Cd^2+ was displaced from EDTA by the addition of an excess of CN Titration of the newly freed EDTA required 27.1 mL of 0.0250 M Ca^2+. What are the concentrations of Cd^2+ and Mn^2+ in the original solution?
Answer:
See explaination
Explanation:
EDTA is a chemical that binds and holds on to (chelates) minerals and metals such as chromium, iron, lead, mercury, copper, aluminum, nickel, zinc, calcium, cobalt, manganese, and magnesium. When they are bound, they can't have any effects on the body and they are removed from the body.
Check attachment for the step by step solution of the given problem.
Use the reaction data in the table below to select the answer choice that best describes this reaction.
Reaction Enthalpy Change
345.7 kJ/mol
Reaction Entropy Change
-25. 3 J/molK
This reaction is never spontaneous.
This reaction is spontaneous at all temperatures.
This reaction is spontaneous at low temperatures.
This reaction is spontaneous at high temperatures
Answer: This reaction is never spontaneous
Explanation:
According to Gibbs equation:
[tex]\Delta G=\Delta H-T\Delta S[/tex]
[tex]\Delta G[/tex] = Gibb's free energy change
[tex]\Delta H[/tex] = enthalpy change
T = temperature
[tex]\Delta S[/tex] = entropy change
A reaction becomes spontaneous when [tex]\Delta G[/tex] = Gibb's free energy change is negative.
[tex]\Delta G=+ve-T(-ve)[/tex]
[tex]\Delta G=+ve+ve[/tex]
[tex]\Delta G=+ve[/tex]
Thus this reaction is never spontaneous
Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory as a primary standard. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP. If 34.10 mL of a barium hydroxide solution are needed to neutralize 2.050 grams of KHP, what is the concentration (mol/L) of the barium hydroxide solution
Answer:
0.1472 mol/L is the concentration of the barium hydroxide solution.
Explanation:
[tex]2KHC_8H_4O_4+Ba(OH)_2\rightarrow Ba(KC_8H_4O_4)_2+2H_2O[/tex]
Mass of potassium hydrogen phthalate = 2.050 g
Molar mass of potassium hydrogen phthalate = [tex]\frac{2.050 g}{204.2 g/mol}=0.01004 mol[/tex]
According to reaction , 2 moles of potassium hydrogen phthalate reacts with 1 mole of barium hydroxide, then 0.01004 moles of potassium hydrogen phthalate will :
[tex]\frac{1}{2}\times 0.01004 mol=0.005020 mol[/tex] of barium hydroxide
Moles of barium hydroxide = 0.005020 mol
Volume of the barium hydroxide solution = 34.10 mL = 0.03410 L
1 mL = 0.001 L
[tex]Molarity=\frac{Moles}{Volume(L)}[/tex]
Molarity of the barium hydroxiude silution :
[tex]=\frac{0.005020 mol}{0.03410 L}=0.1472 mol/L[/tex]
0.1472 mol/L is the concentration of the barium hydroxide solution.
Calculate the approximate volume of a 1.50 mol sample gas at 15.0°C and a pressure at 3.75atm.
Answer:
V= 9.45L
Explanation:
P=3.75atm, V=?, n= 1.5, R= 0.082, T= 15+ 273= 288K
Applying
PV= nRT
Substitute and Simplify
3.75*V= 1.5*0.082*288
V= 9.45L
The approximate volume of a 1.50 mol sample of gas at 15.0°C and a pressure of 3.75 atm is calculated using the Ideal Gas Law to be about 9.20 liters.
To calculate the approximate volume of a 1.50 mol sample of gas at 15.0°C and a pressure of 3.75 atm, we can use the Ideal Gas Law, which is PV = nRT. First, we must convert the temperature from Celsius to Kelvin by adding 273.15 to the Celsius temperature. Then we can solve for V, the volume of the gas.
The conversion from Celsius to Kelvin: T(K) = 15.0 + 273.15 = 288.15 K
Using the Ideal Gas Law constants, R = 0.0821 L·atm/K·mol. Substituting the known values into the Ideal Gas Law equation:
PV = nRT
(3.75 atm) × V = (1.50 mol) × (0.0821 L·atm/K·mol) × (288.15 K)
V = (1.50 mol × 0.0821 L·atm/K·mol × 288.15 K) / 3.75 atm
V = 9.2029 L
Therefore, the approximate volume of the gas sample is about 9.20 liters.
According to VSEPR theory, the molecule PF6- has how many regions of electron density around the central atom (how many electron groups?) (enter a number from 1 to 6) PF6- will have (linear, trigonal planar, tetrahedral, trigonal pyramidal, bent, trigonal bipyramidal, seesaw, T-shaped, octahedral, square pyramidal, square planar) electronic geometry, and (linear, trigonal planar, tetrahedral, trigonal pyramidal, bent, trigonal bipyramidal, seesaw, T-shaped, octahedral, square pyramidal, square planar) molecular geometry.
Answer : The electronic geometry and the molecular geometry of the molecule will be octahedral.
Explanation :
Formula used :
[tex]\text{Number of electron pair}=\frac{1}{2}[V+N-C+A][/tex]
where,
V = number of valence electrons present in central atom
N = number of monovalent atoms bonded to central atom
C = charge of cation
A = charge of anion
The given molecule is, [tex]PF_6^-[/tex]
[tex]\text{Number of electrons}=\frac{1}{2}\times [5+6+1]=6[/tex]
The number of electron pair are 6 that means the hybridization will be [tex]sp^3d^2[/tex] and the electronic geometry and the molecular geometry of the molecule will be octahedral.
The correct number of regions of electron density around the central atom in PF₆- is 6. The electronic geometry of PF6- is octahedral, and the molecular geometry is also octahedral.
To determine the number of electron regions around the central phosphorus atom in PF6-, we count the bonded atoms and any lone pairs on the central atom.
The Lewis structure of PF6- shows that the phosphorus atom is bonded to six fluorine atoms and has no lone pairs since it is surrounded by six bonding groups and has a formal charge of -1, which balances the overall charge of the ion.
Each bonded fluorine contributes one region of electron density, and there are no lone pairs on the phosphorus atom.
Therefore, there are six regions of electron density around the central phosphorus atom, which corresponds to an octahedral electronic geometry.
Since there are no lone pairs, the molecular geometry is the same as the electronic geometry, which is octahedral. This means that all six fluorine atoms are arranged around the central phosphorus atom in a way that they are at the vertices of an octahedron.
In summary, the VSEPR theory predicts that PF6- has six regions of electron density, an octahedral electronic geometry, and an octahedral molecular geometry.
When calcium carbonate is added to hydrochloric acid, calcium chloride, carbon dioxide, and water are produced. CaCO3(s)+2HCl(aq)⟶CaCl2(aq)+H2O(l)+CO2(g) How many grams of calcium chloride will be produced when 25.0 g of calcium carbonate is combined with 14.0 g of hydrochloric acid? mass of CaCl2 :
Answer:
Mass of CaCl₂ produced from the reaction = 21.31 g
Explanation:
The balanced equation for the reaction
CaCO₃(s) + 2HCl(aq) ⟶ CaCl₂(aq) + H₂O(l) + CO₂(g)
How many grams of calcium chloride will be produced when 25.0 g of calcium carbonate is combined with 14.0 g of hydrochloric acid
First of, we need to recognize the limiting reagent in this reaction.
The limiting reagent is the reagent that is totally used up in the chemical reaction; it determines the amount of other reactants that react and the amount of products that will be formed.
To know the limiting reagent, we convert the masses of the reactants given to number of moles.
Number of moles = (mass)/(molar mass)
25.0 g of calcium carbonate
Molar mass of CaCO₃ = 100.0869 g/mol
Number of moles of CaCO₃ present at the start of the reaction = (25/100.0869) = 0.250 moles
14.0 g of hydrochloric acid
Molar mass of HCl = 36.46 g/mol
Number of moles of HCl present at the start of the reaction = (14/36.45) = 0.384 moles
But from the stoichiometric balance of the reaction,
1 mole of CaCO₃ reacts with 2 moles of HCl
If CaCO₃ was the limiting reagent,
0.25 moles of CaCO₃ at the start of the reaction would require 0.50 moles of HCl; which is more than the available number of moles of HCl available at the start of the reaction (0.384 moles)
So, CaCO₃ isn't the limiting reagent.
If HCl is the limiting reagent,
0.384 moles of HCl would require 0.192 moles of CaCO₃ to react with. This is within the limit of CaCO₃ present at the start of the reaction. (0.250 moles)
Hence, HCl is the limiting reagent, it is the reactant that is used up in the reaction and determines the amount of products formed.
Again, from the stoichiometric balance of the reaction,
2 moles of HCl gives 1 mole of CaCl₂
0.384 moles of HCl will give (0.384/2) moles of CaCl₂; that is, 0.192 moles of CaCl₂
We then convert this number of moles to mass.
Mass = (number of moles) × (molar mass)
Molar mass of CaCl₂ = 110.98 g/mol
Mass of CaCl₂ produced by the reaction = 0.192 × 110.98 = 21.30816 g = 21.31 g
Hope this Helps!!!
Answer: 21.09g of Calcium chloride is produced
Explanation: Please see the attachments below
For a pure substance, the liquid and gaseous phases can only coexist for a single value of the pressure at a given temperature. Is this also the case for an ideal solution of two volatile liquids?
Answer:
No, it is not.
Explanation:
Most solutions do not behave ideally. Designating two volatile substances as A and B, we can consider the following two cases:
Case 1: If the intermolecular forces between A and B molecules are weaker than those between A molecules and between B molecules, then there is a greater tendency for these molecules to leave the solution than in the case of an ideal solution. Consequently, the vapor pressure of the solution is greater than the sum of the vapor pressures as predicted by Raoult’s law for the same concentration. This behavior gives rise to the positive deviation.
Case 2: If A molecules attract B molecules more strongly than they do their own kind, the vapor pressure of the solution is less than the sum of the vapor pressures as predicted by Raoult’s law. Here we have a negative deviation.
The benzene/toluene system is an exception, since that solution behaves ideally.
No, in the case of an ideal solution of two volatile liquids the two substances at different state cannot coexist for a single value of pressure at a given temperature.
The ideal solution of the two volatile liquids can exist on different ranges of pressure. Their pressure can be limited to an extent at which either only a trace value of liquid remains and the pressure at which only a trace value of gas exists.Learn more about gas:
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Given the equation representing a system at equilibrium:
PCl5(g) + energy ⇌ PCl3(g) + Cl2(g)
Which change will cause the equilibrium to shift to the right?
(1) adding a catalyst (2) adding more PCl3(g)
(3) increasing the pressure (4) increasing the temperature
Answer:
increasing the temperature
Explanation:
Now look carefully at the reaction equation, notice the inclusion on an energy term on the left hand side;
PCl5(g) + energy ⇌ PCl3(g) + Cl2(g)
The inclusion of an energy term means that the reaction is endothermic. Energy is absorbed as the reaction goes from left to right.
Since energy is absorbed, increasing the temperature (supplying energy in the form of heat) will favour the forward reaction over the reverse reaction in accordance with Le Chatelier's principle. Hence the answer.
Answer:
Option (4) increasing the temperature
Explanation:
PCl5(g) + energy ⇌ PCl3(g) + Cl2(g)
The reaction above clearly indicates endothermic reaction since heat is required for the reaction to proceed to product.
As the heat is supplied, the temperature of reaction increases thereby making the reaction to proceed forward at a much faster rate and hence the equilibrium position will shift to the right. This is in accordance with Le Chatelier's principle will explained that for an endothermic reaction, an increase in temperature will cause the equilibrium position to shift to the right.
False: The highest oxidation state for hydrogen in this reaction is 0 False: The oxidation state of chromium in dichromate is 3. False: The iron half-reaction takes place in an acidic solution. True: The oxidation state of oxygen does not change. False: The oxidizing agent is Cr3 (aq) False: The reducing agent is Fe2 (aq)
The question addresses the oxidation states and redox reaction balancing in chemistry, involving chromium's oxidation state in dichromate and identification of the oxidizing agent.
Explanation:The question involves oxidation states and balancing redox reactions in chemistry. Regarding the oxidation state of hydrogen, it is generally +1 in compounds, not 0. For chromium in dichromate, the oxidation state is +6 (chromium(VI)), not +3. The iron half-reaction might indeed take place in acidic solution, depending on the specific reaction being discussed. The chromate half-reaction needs to have oxygen atoms balanced with water, and hydrogen atoms balanced with hydrogen ions, as indicated in the steps provided. The dichromate ion is a strong oxidizing agent, especially in acidic solution; Cr3+ does not act as the oxidizing agent in typical reactions with dichromate ions.
An aqueous solution is 3.23M in tartaric acid (C4H06). The solution's density is 1.023 g/mL.
Calculate the solution's molality in tartaric acid.
Answer:
Molality = 6.0 m
Explanation:
The molecular weight of tartaric acid = 150.087 g/mol
Given that:
Density of the solution = 1.023 g/mL
Molarity = 3.23M
Density is given as : [tex]Molarity ( \frac{1}{molality } +\frac{mol.wt}{1000} )[/tex]
∴
[tex]1.023 = 3.23 (\frac{1}{molality } +\frac{150.087}{1000} )[/tex]
[tex]\frac{1}{molality } =( \frac{1.023}{3.23} - \frac{150.087}{1000} )[/tex]
[tex]\frac{1}{molality } =0.3167 - 0.1500[/tex]
[tex]\frac{1}{molality } = 0.1667[/tex]
Molality = [tex]\frac{1}{0.1667}[/tex]
Molality = 5.999 m
Molality ≅ 6.0 m
The method used by Joseph Priestley to obtain oxygen made use of the thermal decomposition of mercuric oxide given below. What volume of oxygen gas, measured at 39°C and 725 torr, can be produced from the complete decomposition of 3.97 g mercuric oxide?
Answer:
The volume of the oxygen gas is 0.246 L
Explanation:
Step 1: Data given
Temperature = 39 °C = 312 K
Temperature = 725 torr = 725 / 760 atm = 0.953947 atm
Mass of mercuric oxide = 3.97 grams
Molar mass of mercuric oxide = 216.59 g/mol
Step 2: The balanced equation
2HgO → 2Hg + O2
Step 3: Calculate moles mercuric oxide
Moles = mass / molar mass
Moles HgO = 3.97 grams / 216.59 g/mol
Moles HgO = 0.0183 moles
Step 3: Calculate moles oxyen
For 2 moles HgO we'll have 2 moles Hg and 1 mol O2
For 0.0183 moles HgO we'll have 0.0183/2 = 0.00915 moles O2
Step 4: Calculate volume O2
p*V = n*R*T
⇒with p = the pressure of the gas = 0.953947 atm
⇒with V = the volume of O2 gas = TO BE DETERMINED
⇒with n = the moles of O2 = 0.00915 moles
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 312 K
V = (n*R*T)/p
V = (0.00915 moles * 0.08206 L*atm/mol*K * 312 K ) / 0.953947 atm
V = 0.246 L
The volume of the oxygen gas is 0.246 L
Final answer:
The complete thermal decomposition of 3.97 g of mercuric oxide (HgO) at 39 0C and 725 torr will produce 2.487 Liters of oxygen gas (O2). The calculations involve converting grams to moles using the molar mass of HgO, applying the stoichiometry of the decomposition reaction, and calculating the volume with the ideal gas law.
Explanation:
The question involves the chemical decomposition of mercuric oxide (HgO) to produce oxygen gas (O2) and uses the ideal gas law to calculate the volume of oxygen produced under specific conditions. To solve this problem, we'll use the ideal gas law PV=nRT along with stoichiometry.
Calculate the molar mass of HgO to convert grams to moles.Use stoichiometry to determine the moles of O2 produced from the thermal decomposition of HgO with the chemical equation 2HgO (s)Now, let's provide a step-by-step solution:
Molar mass of HgO = 200.59 g/mol + 15.999 g/mol = 216.589 g/mol.3.97 g HgO * (1 mol HgO / 216.589 g HgO) = 0.01832 mol HgO. According to the equation, 2 moles of HgO produce 1 mole O2, so 0.01832 mol HgO will produce 0.00916 mol O2.725 torr is equivalent to 725 torr * (1 atm / 760 torr) = 0.954 atm.Now convert the temperature to Kelvin: 39 0C + 273.15 = 312.15 K.Using the ideal gas law, PV=nRT, where R is the gas constant 0.0821 L*atm/mol*K, we solve for V: V = nRT/P = (0.00916 mol * 0.0821 L*atm/mol*K * 312.15 K) / 0.954 atm = 2.487 L.Therefore, 2.487 Liters of oxygen gas will be produced from the complete decomposition of 3.97 g of mercuric oxide at 39°C and 725 torr.
Select the following processes that represent a decrease in entropy: Group of answer choices Water is heated in the microwave from 23 oC to 90 oC. 2 NO2(g) → N2O4(g) The sublimation of I2 CO2 gas is dissolved in water to make a carbonated beverage
Answer:
The answers that represent a decrease in entropy are:
-CO2 gas is dissolved in water to make a carbonated beverage
-NO2(g) → N2O4(g)
Explanation:
Since in carbonated drinks, carbon dioxide is in its liquid form, since a pressure is applied to said gas, in this way, when carbon dioxide dissolves in a liquid, its entropy decreases, thus producing a negative change in entropy (the entropy of a gas is higher than the entropy of a liquid).
The number of gaseous reagents is equal to 1-2 = -1. Since it is negative, therefore, entropy is also negative.
Relate energy levels to the amount of energy their electrons have
In atoms, electrons exist on specific, discrete energy levels, which correspond to distinct values of the principal quantum number 'n'. Electricity fills these 'shells' from the lowest to the highest energy state. Transitions between energy levels require definite energy changes.
Explanation:The energy levels of electrons in an atom can be understood using the principal quantum number often denoted by 'n'. Electrons exist only on specific, discrete energy levels and not between them. This principle is known as the quantization of energy. Each energy level is associated with a specific value of 'n', with n = 1, 2, 3, and so on. The greater the 'n' value, the higher the energy level.
Each energy level or shell can be visualized as concentric circles radiating from the nucleus of the atom. Electrons fill these shells starting from the one closest to the nucleus (lowest energy state), filling up to the one furthest from the nucleus (highest energy state). This illustrates the principle of energy states in a metal as in Figure 9.13.
Furthermore, the Bohr atom model suggests that each electron orbit around the nucleus corresponds to a distinct energy level, and each transition between these levels involves a definite energy change. Therefore, the energy levels of electrons in an atom are directly related to the amount of energy possessed by the electrons.
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you need to prepare 250.0 mL of a 1.50 M HCl solution from a 2.00 M HCl stock solution. assuming that the accuracy of the concentration is important, which type of glassware should you use to make the solution
Answer:
I should use a volumetric flask.
Explanation:
If the accuracy of the concentration is important, we need to use a volumetric flask.
Answer:
The glassware appropriate for dilution preparation is a (250 mL) volumetric flask
Explanation:
We know that molarity or concentration of a solution is the number of moles per litres of solution, the molarity and volume of the solution in question can be used to find out how much of the stock solution to be diluted using the formula;
[tex]c = \frac{n}{v}[/tex]
Once the variables are confirmed, a 250 mL solution of 1.50M HCl can be prepared by measuring determined stock solute into a 250mL volumetric flask and the making it upto the 250mL mark. (a measuring cylinder can be used to check accuracy of volume added).
What volume of ammonia gas, measured at 547.9 mmHg and 27.6oC, is required to produce 8.98 g of ammonium sulfate according to the following balanced chemical equation? 2NH3(g) + H2SO4(aq) → (NH4)2SO4(s)
Answer:
4.65 L of NH₃ is required for the reaction
Explanation:
2NH₃(g) + H₂SO₄(aq) → (NH₄)₂SO₄(s)
We determine the ammonium sulfate's moles that have been formed.
8.98 g . 1mol / 132.06 g = 0.068 moles
Now, we propose this rule of three:
1 mol of ammonium sulfate can be produced by 2 moles of ammonia
Therefore, 0.068 moles of salt were produced by (0.068 . 29) / 1 = 0.136 moles of NH₃. We apply the Ideal Gases Law, to determine the volume.
Firstly we do unit's conversions:
27.6°C +273 = 300.6 K
547.9 mmHg . 1 atm / 760 mmHg = 0.721 atm
V = ( n . R . T ) / P → (0.136 mol . 0.082 L.atm/mol.K . 300.6K) / 0.721 atm
V = 4.65 L
Answer:
4.66 L of ammonia gas will be produced
Explanation:
Step 1: Data given
The pressure of ammonia gas = 547.9 mmHg = 0.72092116 atm
Temperature = 27.6 °C = 300.75 K
Mass of ammonium sulfate produced = 8.98 gramms
Molar mass of ammonium sulfate = 132.14 g/mol
Step 2: The balanced equation
2NH3(g) + H2SO4(aq) → (NH4)2SO4(s)
Step 3: Calculate moles (NH4)2SO4
Moles (NH4)2SO4 = mass (NH4)2SO4 / molar mass
Moles (NH4)2SO4 = 8.98 grams / 132.14 g/mol
Moles (NH4)2SO4 = 0.0680 moles
Step 4: Calculate moles NH3
For 1 mol (NH4)2SO4 we need 2 moles NH3
For 0.0680 moles (NH4)2SO4 we need 2*0.0680 = 0.136 moles NH3
Step 5: Calculate volume NH4
p*V=n*R*T
V = (n*R*T)/p
⇒with V = the volume of NH3 = TO BE DETERMINED
⇒with n = the number of moles NH3 = 0.136 moles NH3
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 300.75 K
⇒with p = the pressure of the gas = 0.72092116 atm
V = (0.136 * 0.08206 * 300.75) / 0.72092116
V = 4.66 L
4.66 L of ammonia gas will be produced
Determine the volume (in L) of Cl2(g) required to carry out the following reaction at 794 torr and 625°C using 15.0 g of Fe. The value of R = 0.0821 L atm mol−1 K−1. 2Fe(s) + 3Cl2(g) = 2FeCl3(s)
Answer:
28.5 L of Cl
Explanation:
From PV=nRT
P= 794torr or 1.04 atm
T= 625°C or 898K
R= 0.0821 L atm mol−1 K−1
n= 3 moles
V= ???
V= nRT/P
V=3× 0.0821× 898/1.04
V= 212.7 L
From the balanced reaction equation
112g of iron reacted with 212.7L of Cl
15.0 g of iron will react with 15.0×212.7/112
= 28.5 L of Cl
An analytical chemist is titrating of a solution of hydrazoic acid with a solution of . The of hydrazoic acid is . Calculate the pH of the acid solution after the chemist has added of the solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of solution added. Round your answer to decimal places.
Answer:
ph= 3.53
Explanation:
A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic. The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next higher value.
Check attachment for the step by step solution of the given problem.
The percent by mass of bicarbonate (HCO3−) in a certain Alka-Seltzer product is 32.5 percent. Calculate the volume of CO2 generated (in mL) at 37°C and 1.00 atm if a person were to accidentally ingest a 3.45-g tablet without following instructions. (Hint: The reaction occurs between HCO3− and HCl acid in the stomach.)
Answer:
The volume of carbon dioxide gas generated 468 mL.
Explanation:
The percent by mass of bicarbonate in a certain Alka-Seltzer = 32.5%
Mass of tablet = 3.45 g
Mass of bicarbonate =[tex]3.45 g\times \frac{32.5}{100}=1.121 mol[/tex]
Moles of bicarbonate ion = [tex]\frac{1.121 g/mol}{61 g/mol}=0.01840 mol[/tex]
[tex]HCO_3^{-}(aq)+HCl(aq)\rightarrow H_2O(l)+CO_2(g)+Cl^-(aq)[/tex]
According to reaction, 1 mole of bicarbonate ion gives with 1 mole of carbon dioxide gas , then 0.01840 mole of bicarbonate ion will give:
[tex]\frac{1}{1}\times 0.01840 mol=0.01840 mol[/tex] of carbon dioxide gas
Moles of carbon dioxide gas n = 0.01840 mol
Pressure of the carbon dioxide gas = P = 1.00 atm
Temperature of the carbon dioxide gas = T = 37°C = 37+273 K=310 K
Volume of the carbon dioxide gas = V
[tex]PV=nRT[/tex] (ideal gas equation)
[tex]V=\frac{nRT}{P}=\frac{0.01840 mol\times 0.0821 atm L/mol K\times 310 K}{1.00 atm}=0.468 L[/tex]
1 L = 1000 mL
0.468 L =0.468 × 1000 mL = 468 mL
The volume of carbon dioxide gas generated 468 mL.
Final answer:
The volume of CO2 generated from a 3.45-g Alka-Seltzer tablet containing 32.5% bicarbonate is approximately 469.2 mL when reacted with stomach acid at 37°C and 1.00 atm.
Explanation:
To calculate the volume of CO2 generated from the reaction of bicarbonate (HCO^{3−}) with HCl in the stomach, we can use the provided mass percent of bicarbonate in the Alka-Seltzer tablet and the reaction stoichiometry. The balanced equation for the reaction between sodium bicarbonate and hydrochloric acid is:
NaHCO3(s) + HCl(aq) → NaCl(aq) + H2O(l) + CO2(g)
Assuming the percent by mass of bicarbonate is 32.5%, a 3.45-g tablet would contain 1.12125 g of HCO3−. The molar mass of HCO^{3−} is approximately 61 g/mol, which corresponds to 0.0184 moles of HCO^{3−}. Since the reaction produces one mole of CO2 for each mole of HCO3−, we can use the ideal gas law to calculate the volume of CO2.
At STP (0°C and 1 atm), one mole of any gas occupies 22.4 L. However, we're given conditions of 37°C and 1.00 atm. To adjust for the temperature, we can use the combined gas law:
V2 = (V1 × T2 × P1) / (T1 × P2)
Where:
V1 = 22.4 LT1 = 273 K (STP temperature)T2 = 310 K (37°C in kelvin)P1 and P2 = 1 atm (pressure is constant)Thus:
V2 = (22.4 L × 310 K) / 273 K
V2 is the volume of CO2 at the new conditions, which is approximately 25.5 L/mol. Since we have 0.0184 moles of HCO^{3−}, the volume of CO2 produced would be 0.0184 moles × 25.5 L/mol = 0.4692 L or 469.2 mL.
If you left a block of dry ice in a bowl at room temperature all day, what would happen to it?
Answer:
It would evaporate.
Explanation:
If you left it on room temperature it would evaporate.