You are performing a titration of a triprotic acid, when you spill water on your lab notebook. you can read that: pka 1 = 1.40, pka 3 = 9.80. you have determined experimentally that the ph at the first equivalence point is 3.35, and the ph at the second equivalence point is 7.55. what is pka 2 for this acid?
the height of a column of mercury in barometer is 754.3mm. what us the atmospheric pressure in atm. in kPa.
Final answer:
To convert the height of a column of mercury in a barometer to atmospheric pressure in atm and kPa, divide the height of the column by 760 to get the pressure in atm, and then multiply the atmospheric pressure by 101.325 to get the pressure in kPa.
Explanation:
To convert the height of a column of mercury in a barometer to atmospheric pressure in atm and kPa, we can use the conversion factors. At sea level, the standard atmospheric pressure is 760 mm Hg (millimeters of mercury) or 1 atm. Using this information, we can calculate the atmospheric pressure in atm and kPa.
To convert from mm Hg to atm, divide the height of the column by 760:
Atmospheric pressure (in atm) = 754.3 mm Hg / 760 mm Hg = 0.992 atm.
To convert from atm to kPa, multiply the atmospheric pressure by 101.325 (the number of kilopascals in 1 atm):
Atmospheric pressure (in kPa) = 0.992 atm * 101.325 kPa/atm = 100.45 kPa.
This diagram would represent the enthalpy changes in which of the following?
boiling liquid
hot pack
cold pack
melting solid
A part of the periodic table is shown. A portion of the fifteenth and sixteenth columns of the periodic table is shown. Column 15 from top to bottom reads seven nitrogen, 15 phosphorus, and 33 arsenic. Column 16 reads eight oxygen, 16 sulfur, and 34 selenium. Which of the following elements is more reactive than the others? Nitrogen (N) Oxygen (O) Selenium (Se) Sulfur (S)
Answer: The correct answer is oxygen.
Explanation:
Reactivity is defined as the tendency of an atom to loose or gain electrons.
The reactivity of non-metal increases as we move from left to right in a period and decreases as we move from top to bottom in a group.
The given elements are non-metals as they belong to group 15 and group 16 of the periodic table.
For the given options:
Nitrogen (N): It belongs to Group 15 and Period 2 of the periodic table.
Oxygen (O): It belongs to Group 16 and Period 2 of the periodic table.
Selenium (Se): It belongs to Group 16 and Period 4 of the periodic table.
Sulfur (S): It belongs to Group 16 and Period 3 of the periodic table.
From the given elements, the most reactive element will be oxygen.
Order of reactivity of metals follows:
[tex]\text{Oxygen}>\text{Nitrogen}>\text{Sulfur}>\text{Selenium}[/tex]
Hence, the correct answer is oxygen.
If the specific heat of water is 4.186 kJ/kg∙°C, how much heat is required to increase the temperature of 1.2 kg of water from 23 °C to 39 °C?
To calculate the energy required to raise the temperature of any given substance, here's what you require:
The mass of the material, m
A sample of Ni(CO)4, a toxic transition-metal complex, has 5.23 x 10^24 atoms of carbon. How many atoms of Ni does it contain?
A. 6.02 x 10^23 atoms
B. 1.50 x 10^23 atoms
C. 1/4 atom
D. 20.9 x 10^23 atoms
E. 1.31 x 10^24 atoms
Answer: The correct answer is Option E.
Explanation:
We are given a chemical compound having formula [tex]Ni(CO)_4[/tex]
In 1 mole of the compound, 1 mole of nickel atom, 4 moles of carbon atom and 4 moles of oxygen atom are present.
According to mole concept:
1 mole of a substance contains [tex]6.022\time 10^{23}[/tex] number of particles
Number of carbon atoms in compound = [tex]4\times 6.022\times 10^{23}[/tex]
Number of nickel atoms in compound = [tex]1\times 6.022\times 10^{23}[/tex]
We are given:
Number of carbon atoms = [tex]5.23\times 10^{24}[/tex]
To calculate the number of nickel atoms for given amount of carbon atom, we use unitary method:
When [tex]4\times 6.022\times 10^{23}[/tex] number of carbon atoms are present, then [tex]6.022\times 10^{23}[/tex] number of nickel atoms are also present.
So, when [tex]5.23\times 10^{24}[/tex] number of carbon atoms are present, then [tex]\frac{4\times 6.022\times 10^{23}}{6.022\times 10^{23}}\times 5.23\times 10^{24}=1.31\times 10^{24}[/tex] number of nickel atoms are also present.
Hence, the correct answer is Option E.
Which atom would be expected to have a half-filled 4s subshell?
The element Vanadium (V) is expected to have a half-filled 4s subshell due to its unique electron configuration that favors stability, with the configuration shifting to [Ar] 3d54s1 to achieve a half-filled 4s orbital.
Explanation:An atom expected to have a half-filled 4s subshell is Vanadium (V), with an atomic number of 23. The electronic configuration is [Ar] 3d34s2. However, due to the stability offered by half-filled subshells, one electron from the 4s orbital will move to the 3d subshell, resulting in the configuration of [Ar] 3d54s1, which is half-filled in its 4s subshell.
Other elements like Chromium (Cr) and Copper (Cu) also exhibit adjustments in their electron configurations in favor of stability with either half-filled or fully-filled d subshells. The electron configuration of Cr is [Ar] 3d54s1 and for Cu, it is [Ar] 3d104s1, both deviating from what would be predicted by the Aufbau principle, highlighting the special stability of half-filled and fully-filled subshells.
If a reaction mixture initially contains a co concentration of 0.1470 and a cl2 concentration of 0.175 at 1000k. what is the equilibrium concentration of co at 1000 k?
What energy conversion is occurring in a solar panel?
a). Nuclear energy is converted to electrical energy
b). Electrical energy is converted to radiant energy
c). Radiant energy is converted to electrical energy
d). Radiant energy is converted to nuclear energy
Which of the following is NOT true of fusion?
Question 9 options:
2 or more smaller atoms come together to create a larger atom
Occurs in the stars, such as the sun
Used in nuclear power plants
High density, high temperature is required
what is the slowest process sea level changes, erosion or uplift
Three 5-l flasks, fixed with pressure gauges and small valves, each contains 4 g of gas at 273 k. flask a contains h2, flask b contains he, and flask c contains ch4. rank the flask contents in terms of
The ranking of the flask contents in terms of molar masses is Flask C (CH4), Flask A (H2), Flask B (He)
Explanation:The ranking of the flask contents in terms of
Flask C (CH4)Flask A (H2)Flask B (He)This ranking is based on the molar masses of the gases. The molar mass of CH4 is 16 g/mol, the molar mass of H2 is 2 g/mol, and the molar mass of He is 4 g/mol.
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Which would aid a student in preparedness for a lab
Answer:
reading the lab manual before class
Explanation:
The laboratory is a highly regulated and controlled environment. Within a laboratory many rules must be followed so that no contamination occurs or deterioration of the experiments being performed in the laboratory. All of this can be intimidating for a first-time student entering the lab, so it is recommended that the student prepare before leaving so that no accidents can occur.
The best way for a student to prepare before going to a lab is to read the lab manual before class. This way, the student knows everything they can do and cannot do inside a laboratory and all the guidelines needed for this environment.
Name the following compound: CH3 – CH2 – CH2 – O – CH2 – CH2 – CH2 – CH3 1: butyl propyl ether. 2:propyl butyl ether. 3: 3-butyl propyl ether. 4: 4-propyl butyl ether.
The given compound is named as propyl octyl ether.
Explanation:The given compound is CH3 – CH2 – CH2 – O – CH2 – CH2 – CH2 – CH3. To name this compound, we need to identify the longest carbon chain connected to the oxygen atom. In this case, it is an eight-carbon chain, so the parent chain is octane. Since the oxygen atom is connected to the second carbon atom in the chain, the prefix propyl is used. The compound is then named as propyl octyl ether.
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Draw the diazonium cation formed when cytosine reacts with nano2 in the presence of hcl.
The diazonium cation formed when cytosine reacts with Nano2 in the presence of HCl is CH+N2+ C-.
Explanation:The diazonium cation formed when cytosine reacts with Nano2 in the presence of HCl can be represented as:
CH+N2+C-
In this structure, the cytosine molecule donates its amino group (NH2) to the diazonium cation (N2+) while losing a hydrogen ion (H+). The presence of HCl helps in the formation of the diazonium cation.
What smell/ fragrant odor should you expect, when 1- pentanol and acetic acid undergo esterification?
A) foul and pungent smell
B) raspberries
C) pear fragrances
D) mint like smell wintergreen
How many moles of al does 13.49 g of al represent?
What is one reason why rock layers are not horizontal?
A) they were formed at and angle
B) a force pushed the rock layers after they were formed
C)they were formed vertically
D)the area was once covered by water
Your awnser is the awnser B).
How many moles in 1.3g sodium bicarbonate
When concentrated [tex]CaCl_{2}(aq)[/tex] is added to [tex]Na_{2}HPO_{4}[/tex], a white precipitate forms that is 38.7% Ca by mass. Write a net ionic equation representing the probable reaction that occurs.
When concentrated is added to , a white precipitate forms that is 38.7% Ca by mass a net ionic equation is CO₃²⁻ ( aqueous ) + Ca₂²⁻( aqueous ) ⇒ CaCO3 (s)
What is molecular formula ?Chemical element symbols, numbers, and occasionally additional symbols like parentheses, dashes, brackets, commas, and plus and minus signs are used in a chemical formula to represent information about the chemical proportions of the atoms that make up a certain chemical compound or molecule.
Molecular formula:
Na₂CO₃ ( aq ) + CaCl₂ ( aq ) = CaCO₃ ( s ) + 2 NaCl
Ionic formula:
2 Na+ ( aq ), CO₃²⁻ ( aq ), Ca₂ ( aq ), and 2 Cl⁻ ( aq ) result in CaCO3²⁻ (s) +2 Na+ ( aq ) and 2 Cl⁻ (aq)
Net ionic formula
CO₃²⁻ ( aqueous ) + Ca₂²⁻( aqueous ) ⇒ CaCO3 (s)
Thus, When concentrated is added to , a white precipitate forms that is 38.7% Ca by mass a net ionic equation is CO₃²⁻ ( aqueous ) + Ca₂²⁻( aqueous ) ⇒ CaCO3 (s)
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Final answer:
The probable reaction between concentrated CaCl₂(aq) and Na₂HPO₄ forms calcium phosphate, Ca₃(PO₄)₂, as a white precipitate. The net ionic equation for the formation of this precipitate is 3Ca²⁺(aq) + 2PO₄³⁺(aq) → Ca₃(PO₄)₂(s). This demonstrates the common ion effect, decreasing the solubility of a sparingly soluble salt.
Explanation:
When concentrated CaCl₂(aq) is added to Na₂HPO₄, it is likely that a precipitation reaction occurs resulting in the formation of calcium phosphate, which is very slightly soluble in water. The white precipitate formed is most probably calcium phosphate, Ca₃(PO₄)₂, which is 38.7% Ca by mass.
The net ionic equation for the reaction that would lead to the formation of this precipitate is:
3Ca²⁺(aq) + 2PO₄³⁺(aq) → Ca₃(PO₄)₂(s)
Through this reaction, we see the common ion effect, which reduces the solubility of calcium phosphate in the presence of additional Ca²⁺ ions provided by the CaCl₂, leading to the precipitation of Ca₃(PO₄)₂.
A sample of an ideal gas has a volume of 2.31 l at 287 k and 1.10 atm. calculate the pressure when the volume is 1.45 l and the temperature is 298 k.
Final answer:
To calculate the new pressure of an ideal gas when the volume decreases to 1.45 L and the temperature increases to 298 K, the combined gas law is used. The final pressure is found to be approximately 1.803 atm after substituting the given initial conditions and solving for the final pressure.
Explanation:
The question relates to the behavior of an ideal gas when it undergoes changes in volume, pressure, and temperature. To solve for the new pressure when the volume and temperature of a gas sample change, we use the combined gas law, which states that the ratio of the product of pressure and volume to the temperature is constant for a fixed amount of gas (P₁ * V₁) / T₁ = (P₂ * V₂) / T₂).
Given:
P₁ = 1.10 atm
V₁ = 2.31 L
T₁ = 287 K
V₂ = 1.45 L
T₂ = 298 K
We need to find the final pressure P₂.
To find the final pressure P2, we rearrange the combined gas law equation:
P₂ = (P₁ * V₁ * T₂) / (V₂ * T₁)
Now we plug in the known values:
P₂ = (1.10 atm * 2.31 L * 298 K) / (1.45 L * 287 K)
P₂ = (750.38 atm*L*K) / (416.15 L*K)
P₂ = 1.803 atm (rounded to three significant figures)
The final pressure of the gas when the volume is 1.45 L and the temperature is 298 K is approximately 1.803 atm.
Which statement best describes evolution?
A. Species have changed over time
B. Traits acquired during a lifetime are Passed to offspring
C. Earths organisms have not changed overtime
D. All of earths organisms were formed at the same time
The balloon Spirit of Freedom, flown around the world by American Steve Fossett in 2002, contained 550,000 cubic feet of helium. How much PΔV work was done by the balloon on the surrounding atmosphere, assuming atmospheric pressure was 1.00 atm while the balloon was being inflated?
The PΔV work done by the balloon Spirit of Freedom on the surrounding atmosphere, assuming 1.00 atm pressure during inflation, can be calculated using the formula W = -PΔV, resulting in -1.577 x 10¹ Joules after converting the given volume and pressure to scientific units.
Explanation:The student is asking about the PΔV work done by a helium balloon on the surrounding atmosphere during its inflation. We assume that the atmospheric pressure is constant during the process. The equation for work done during expansion or compression of a gas at constant external pressure is W = -PΔV. Since the external pressure is given as 1.00 atm, and we know the volume change (ΔV), which is 550,000 cubic feet, we can calculate the work done.
First, to use the equation, we should convert the volume from cubic feet to liters, as standard scientific units are preferred. 550,000 cubic feet equals about 15,562,000 liters (since 1 cubic foot equals approximately 28.317 liters). The pressure should also be converted to Pascals (since 1 atm equals 101,325 Pa).
Calculations:
Convert volume: 550,000 ft³ * 28.317 L/ft³ = 15,562,000 LConvert pressure: 1.00 atm * 101,325 Pa/atm = 101,325 PaCalculate PΔV work: W = -PΔV = -(101,325 Pa)(15,562,000 L) [Since L and m³ are not direct substitutes, we should convert liters to m³ by dividing by 1,000]Final calculation: W = -(101,325 Pa)(15,562 m³) = -1.577 x 10¹ J (since 1 L = 0.001 m³)Learn more about PΔV work here:https://brainly.com/question/34685555
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This radioactive particle, emitted from carbon-14, has a negative charge. It contains sufficient energy to burn human skin and can pass through paper. It is a(n) ___________ particle.
The radioactive particle, emitted from carbon-14, has a negative charge and is known as a Beta particle.
What is a Beta particle?A beta particle can be described as a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus in beta decay. There are β− decay and β+ decay, which produce electrons and positrons respectively. Beta particles have negative charge electrons released by the nucleus on the decay splitting of a neutron.
Beta particles have an energy of 0.5 MeV and a range of about one meter in the air. Beta particles are ionizing radiation but less ionizing than alpha particles. The higher the ionizing effect, the more damage to the living tissue of human tissue.
The beta particle has medium penetrating power and medium ionizing power. Although the beta particles emitted by different radioactive materials vary in energy and this radioactive carbon-14 also emits beta particles.
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Water molecules are listed from A to B to C in
Answer: Option (B) is the correct answer.
Explanation:
A state of matter where molecules are held together by strong intermolecular forces of attraction are known as solid substances. As a result, they are unable to move from their initial place but they can vibrate at their mean position.
Hence, in solid substances the molecules have low kinetic energy.
In liquids, the molecules are held by less strong intermolecular forces of attraction as compared to solids. Due to which they are able to slide past each other. Hence, they have medium kinetic energy.
In gases, the molecules are held by weak Vander waal forces. Hence, they have high kinetic energy due to which they move rapidly from one place to another leading to more number of collisions.
Thus, we can conclude that water molecules are listed from A to B to C in least to greatest motion.
Determine the rate of a reaction that follows the rate law rate = k a m b i where
Final answer:
The rate of a reaction is determined by the rate law, which includes the concentration of reactants, the rate constant k, and the reaction orders m and n. These factors must be determined experimentally.
Explanation:
The rate of a reaction can be determined by the rate law which, for a given reaction, may have the form rate = k [A]m [B]n, where [A] and [B] are the molar concentrations of the reactants, k is the rate constant, and m and n are the reaction orders. To determine the rate of a reaction, one needs to know the values of the rate constant k and the reaction orders m and n, which must be obtained experimentally.
The value of the rate constant k is characteristic of the reaction under specific conditions such as temperature and pressure, and though it is independent of the reactant concentrations, it does vary with temperature. The units for k depend on the reaction orders m and n and the desired units for the rate, which are typically moles per liter per second (mol/L/s). For instance, if the concentration units are mol³/L³, then the units for k should adjust accordingly to ensure the rate remains in terms of mol/L/s.
A student decomposed 3.67g of copper (ii) hydroxide into copper (ii) oxide. how many ml of 3m h2so4 is need to react with all the copper (ii) oxide?
Josh decided to mix some vinegar with baking soda. He knew that a reaction occurred because he made careful observations. He noted that the mixture started to foam up and bubble and was white in color. How did Josh know that a chemical reaction occured? He was sure a reaction occurred because of
A) the formation of a gas.
B) the color of the mixture.
C) the smell of the vinegar.
D) the volume of the mixture.
Answer: its A
Explanation: i did the test myself so i know its A
Which of the following statements describes an interaction between the geosphere and biosphere?
A.Soil acidity affects plant growth
B.Polar animals find their habitat in frozen ice.
c. Wind energy is used to create electrical power.
DLevel of precipitation has an impact on crop yield
Answer:
The correct answer is A) Soil acidity affects plant growth.
Explanation:
What happens when you place a plant in soil and of course add water? The soil helps it grow.
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Consider this reaction: 2Al(s) + 3 CuCl2(aq) → 2AlCl3(aq) + 3 Cu(s) If the concentration of CuCl2 drops from 1.000 M to 0.655 M in the first 30.0 s of the reaction, what is the average rate of reaction over this time interval?