Answer:
0.425
Explanation:
Answer:
0.452
Explanation:
Extend your thinking: Why do you think the temperature does not change much during a phase change? If possible, discuss your answer with your classmates and teacher.
Answer:
The rate of temperature change does not stay constant and decreases over time because the temperature difference decreases over time.
Explanation:
The temperature difference is due to Thermal Equilibrium
Looking at the heating curves for water (H2O) and ethyl alcohol (C2H5OH), formulate an explanation for the difference in heats of vaporization (2260 J/g for water and 854 J/g for ethyl alcohol).
Answer:
A)They both exhibit hydrogen bonding. However, water has more hydrogens available for hydrogen bonding. Therefore, it requires more heat energy to convert it from a liquid to a gas
Explanation:
USA Test Prep Answer
Where does filtration of the blood occur within the kidneys?
Answer:
takes place in the glomerulus
Explanation:
which is the vascular beginning of the nephron . Approximately one-fourth of the blood flow from cardiac output circulates through the kidney, the greatest rate of blood flow for any organ .
The filtration of the blood in the kidneys occurs in the glomerulus, where most solutes are filtered out by glomerular filtration.
Filtration of the Blood in the Kidneys:
The filtration of the blood in the kidneys primarily occurs in the glomerulus. The glomerulus is a network of capillaries at the beginning of a nephron. When blood flows through the glomerulus, most solutes, except for proteins, are filtered out into the glomerulus by a process called glomerular filtration. The filtrate is then collected in the renal tubules, where it undergoes further processing to form urine.
This process begins with glomerular filtration, continues with tubular reabsorption in the proximal convoluted tubule (PCT), and ends with tubular secretion. Finally, the collecting ducts gather the filtrate, now called urine, which is passed on to the ureters and then eliminated from the body.
Consider the following errors that could be made when running TLC. Indicate what should be done to correct the error. a. A two-component mixture containing 1-octene and 1, 4-dimethylbenzene gave only one spot with an Rf value of 0.95. The solvent used was acetone.
Final answer:
To correct a high Rf value of 0.95 in TLC, decrease the polarity of the mobile phase by using a less polar solvent and ensure the sample is not too concentrated for improved separation and accurate Rf values.
Explanation:
When running Thin Layer Chromatography (TLC), a high Rf value of 0.95 implies that the sample has moved almost as far as the solvent front, suggesting that the mobile phase is too polar. To correct this and achieve better separation, the polarity of the mobile phase should be decreased.
Using a less polar solvent, such as a mixture of hexanes and ethyl acetate, instead of pure acetone might provide better separation of the components 1-octene and 1, 4-dimethylbenzene.
Additionally, ensuring that the samples are not too concentrated can lead to more accurate Rf values and better spot definition. A correctly run TLC should show the desired component with an Rf around 0.35, separated from other spots by at least 0.2 Rf units.
A solution is prepared by dissolving 15.0 g of NH3 in 250 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH3 in the solution is _____.A) 16.8B) 0.940C) 0.0597D) 0.922E) 0.0640
Answer:
Mole fraction of [tex]NH_{3}[/tex] in solution is 0.0597.
Explanation:
Molar mass of [tex]NH_{3}[/tex] = 17.031 g/mol
Molar mass of [tex]H_{2}O[/tex] = 18.015 g/mol
No. of moles = (mass)/(molar mass)
So, 15.0 g of [tex]NH_{3}[/tex] = [tex]\frac{15.0}{17.031}[/tex] moles of [tex]NH_{3}[/tex] = 0.8807 moles of [tex]NH_{3}[/tex]
250 g of [tex]H_{2}O[/tex] = [tex]\frac{250}{18.015}[/tex] moles of [tex]H_{2}O[/tex] = 13.88 moles of [tex]H_{2}O[/tex]
So, Mole fraction of [tex]NH_{3}[/tex] in the solution = (no.of moles of [tex]NH_{3}[/tex] )/(total no. of moles) = [tex]\frac{0.8807}{0.8807+13.88}[/tex] = 0.0597
Hence, mole fraction of [tex]NH_{3}[/tex] in solution is 0.0597.
If a sample gas is collected over water. The atmospheric pressure is 778 mm and the temperature is 30°C. If the vapor pressure of water at 30 C is 31.8 mm, what is the pressure of the gas?
Answer:
P = 746.2 mmHg or 0.9818 atm
Explanation:
First, we have a sample gas (This can be hydrogen, argon, nitrogen or any other gas) that was collected with a pressure of 778 mmHg. We also know the vapor pressure which is 31.8 mmHg. To get the pressure that the gas is exerting, we can assume that the atmospherical pressure is the total pressure of the whole system. Therefore we can use the following expression:
Pt = Pw + Pg (1)
Where:
Pt: total pressure
Pw: water pressure
Pg: gas pressure
From (1) we can solve for the gas pressure and have:
Pg = Pt - Pw
Replacing the data we have:
Pg = 778 - 31.8
Pg = 746.2 mmHgThis would be the pressure of the gasIf you want this value in atm, you should divide it by 760 mmHg (Conversion from mmHg to atm):
Pg = 746.2 / 760
Pg = 0.9818 atmHow many moles are in 4.20 g of SO2?
Answer:
0.066 mole SO₂
Explanation:
moles = mass in grams / formula weight
= 4.2g/64g/mol = 0.066 mole SO₂
Magnesium nitride is formed in the reaction of magnesium metal and nitrogen gas. 4.0 mol of nitrogen is reacted with 6.0 mol of magnesium. The result is…..
a. 2.0 mol of magnesium nitride and 2.0 mol excess nitrogen
b. 4.0 mol of magnesium nitride and 2.0 mol excess magnesium
c. 6.0 mol of magnesium nitride and 3.0 mol excess nitrogen
d. No product because the reactants are not in the correct mole ratio
Answer:
The correct answer is A
We'll have 2.0 moles of magnesium nitride produced and and excess of 2.0 moles nitrogen gas
Explanation:
Step 1: Data given
Number of moles nitrogen gas (N2) = 4.0 moles
Number of moles magnesium = 6.0 moles
Step 2: The balanced equation
3Mg + N2 → Mg3N2
Step 3: Calculate the limiting reactant
For 3 molesmagnesium (Mg) we need 1 mol nitrogen gas (N2) to react, to produce 1 mol magnesium nitride (Mg3N2)
Magnesium is the limiting reactant. It will completely be consumed 6.0 moles. Nitrogen is in excess. There will react 6.0 / 3 = 2.0 moles
There will remain 4.0 - 2.0 = 2.0 moles N2
Step4: Calculate moles Mg3N2
For 3 molesmagnesium (Mg) we need 1 mol nitrogen gas (N2) to react, to produce 1 mol magnesium nitride (Mg3N2)
For 6.0 moles Mg we'll have 6.0 / 3 = 2.0 moles Mg3N2
The correct answer is A
We'll have 2.0 moles of magnesium nitride produced and and excess of 2.0 moles nitrogen gas
The correct answer is a. 2.0 moles of magnesium nitride are formed when 6.0 moles of magnesium react with 4.0 moles of nitrogen, leaving 2.0 moles of nitrogen unreacted as excess.
Explanation:The formation of magnesium nitride involves a reaction between magnesium metal and nitrogen gas. Magnesium forms a Mg2+ ion, which is a cation, by losing two electrons. Nitrogen, a non-metal, forms an anion with a charge of 3-. Therefore, the formula for magnesium nitride is Mg3N2, indicating that three magnesium ions react with two nitrogen ions to form one formula unit of magnesium nitride.
The balanced chemical equation for the formation of magnesium nitride is:
3Mg + N2 → Mg3N2
Given that 4.0 moles of nitrogen is reacted with 6.0 moles of magnesium, we can determine the limiting reactant and calculate the product formed. The molar ratio of Mg to N2 in the equation is 3:1, meaning three moles of Mg are required for every mole of N2. Therefore, 6.0 moles of Mg would completely react with 2.0 moles of N2 to produce magnesium nitride. Since we started with 4.0 moles of nitrogen, we have an excess of nitrogen, and magnesium is the limiting reactant.
The result is that all of the magnesium reacts and you would produce 2.0 moles of magnesium nitride with 2.0 moles of nitrogen left over as excess. Hence, the correct answer to the student's question is option a.
Which equation represents a single replacement reaction that can occur?
A. 2 Cu + FeSO4 → Fe + Cu2SO4
B. Ag + KNO3 → K+ AgNO3
C. l2 + MgCl2 → Cl2 + Mgl2
D. K+ NaF → KF + 2 Na
Given the reactant side of the total ionic equation for the neutralization reaction of ammonium hydroxide (NH4OH) with hydrochloric acid (HCl), write the total ionic equation (also known as the complete ionic equation) by entering both the reactant and the product species, separated by the reaction arrow.
Final answer:
The total ionic equation for the neutralization reaction of ammonium hydroxide with hydrochloric acid expresses all components as ions and after removing spectator ions, the net ionic equation is OH⁻(aq) + H⁺(aq) → H₂O(l).
Explanation:
To write the total ionic equation for the neutralization reaction of ammonium hydroxide (NH₄OH) with hydrochloric acid (HCl), we need to express all soluble substances as ions. Ammonium hydroxide can be represented as NH₄⁺(aq) and OH⁻(aq) since it partially dissociates in solution. The hydrochloric acid fully dissociates into H⁺(aq) and Cl⁻(aq).
The total ionic equation is as follows:
NH₄⁺(aq) + OH⁻(aq) + H⁺(aq) + Cl⁻(aq) → NH₄⁺(aq) + Cl⁻(aq) + 2H₂O(l)
The net ionic equation, which shows the actual chemical change, is produced by removing the spectator ions (NH₄⁺ and Cl-), resulting in: OH⁻(aq) + H⁺(aq) → H₂O(l)
Final answer:
The total ionic equation for the neutralization reaction between ammonium hydroxide and hydrochloric acid is NH4+(aq) + OH-(aq) + H+(aq) + Cl-(aq) → NH4+(aq) + Cl-(aq) + H2O(l), with H+(aq) + OH-(aq) → H2O(l) as the net ionic equation.
Explanation:
The total ionic equation for the neutralization reaction of ammonium hydroxide (NH4OH) with hydrochloric acid (HCl) shows each species in its ionic form. The reactants ammonium hydroxide and hydrochloric acid dissociate in water to form NH4+ (aq), OH- (aq), H+ (aq), and Cl- (aq). In a complete ionic equation, all of the ions are shown as they exist in solution before and after the reaction:
NH4+ (aq) + OH- (aq) + H+ (aq) + Cl- (aq) → NH4+ (aq) + Cl- (aq) + H2O(l)
After the reaction, ammonium ions and chloride ions remain in solution while water is formed as the product. However, since ammonium ions (NH4+) are spectator ions in this reaction, they can be omitted to provide the net ionic equation:
H+ (aq) + OH- (aq) → H2O(l)
The net ionic equation indicates that the hydrogen ions (H+ from the hydrochloric acid) combine with the hydroxide ions (OH- from the ammonium hydroxide) to form water, which is a characteristic outcome of a neutralization reaction.
Select the more electronegative element in each pair.a.Cl or Fb.Se or Oc.N or Asd.Na or Mg
Answer:
The answer to your question is below
Explanation:
Electronegativity is a measure of how strongly atoms attract electrons to themselves.
Process
Look for the electronegativity of each element and compare.
a) Cl = 3.16 F = 3.98 Fluorine has a higher electronegativity
b) Se = 2.55 O = 3.44 Oxygen has a higher electronegativity
c) N = 3.04 As = 2.18 Nitrogen has a higher electronegativity
d) Na = 0.93 Mg = 1.31 Magnesium has a higher electronegativity
The more electronegative elements among the pairs are F (fluorine), O (oxygen), N (nitrogen), and Na (sodium). These are determined based on their positions in the periodic table, where electronegativity generally increases from left to right and decreases from top to bottom.
Explanation:Electronegativity is a measure of the ability of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used electronegativity scale and it ranges from 0 to 4.
In the pair Cl (chlorine) and F (fluorine), F is more electronegative.In the pair Se (selenium) and O (oxygen), O is more electronegative.In the pair N (nitrogen) and As (arsenic), N is more electronegative.In the pair Na (sodium) and Mg (magnesium), Na is more electronegative.Generally, electronegativity increases from left to right across a period and decreases moving down a group or column in the periodic table. Therefore, elements on the top right corner of the periodic table (excluding noble gases) are the most electronegative.
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Bromelain works by breaking the enzymes that cause browning into smaller molecules. Explain how the reaction that breaks up the enzymes occurs.
Bromelain separates the amino acids in the enzymes that cause browning by breaking the peptide bonds. The pH of a solution determines the charge of certain R groups.
Amino acids are defined as the substances which are considered to be the monomers of proteins.Every amino acid has the same structure consisting of a central carbon which is bonded to an amino group , carboxyl group and a hydrogen.
Each amino acid also has another atom or a group of atoms bonded to the alpha carbon which are also known as the R group or the variable group of the side chain.There are 20 common amino acids present in natural proteins and each amino acid has the same backbone.
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Which is the best example of an organism's niche shown in
the picture?
O
The environment contains several of the same species
of coral
The shallow area of the ocean meets the needs of the
coral and the fish
The ocean has fish and coral that live in the same area.
The coral take in food from the water and provide
shem for the fish
Answer:
THE ANSWER IS (D)
Explanation:
Your WelcomeAnswer:
it's D
Explanation:
Which element has the strongest attraction for electrons?
boron
hydrogen
fluorine
80%
nitrogen
Answer:
The answer is Flourine
Which is the correct order of increasing standard molar entropy for the noble gases?
He ≤ Ne ≤ Kr ≤ Ar
He ≤ Ne ≤ Ar ≤ Kr
Ne ≤ He ≤ Ar ≤ Kr
Kr ≤ Ar ≤ Ne ≤ He
Answer:
The correct order of increasing standard molar entropy for the noble gases is He ≤ Ne ≤ Ar ≤ Kr
Explanation:
Entropy is the measure of degree of disorderliness or randomness of a substance. Entropy increases with increasing number of electron present in an atom due to increased repulsive force of the electrons. Therefore, the standard entropy of a substance increases with an increase in their atomic masses.
For the given noble gases in this question, Helium (He) has the least atomic mass while Krypton (Kr) has the highest atomic mass.
Thus, the correct order of increasing standard molar entropy for the noble gases is He ≤ Ne ≤ Ar ≤ Kr
Final answer:
The increasing standard molar entropy for noble gases is He ≤ Ne ≤ Ar ≤ Kr, due to growing atomic number and electronic complexity down the group.
Explanation:
The correct order of increasing standard molar entropy for the noble gases is He ≤ Ne ≤ Ar ≤ Kr. This is because entropy generally increases with atomic number due to increased electronic complexity and atomic mass. As you move down the group in the periodic table, noble gases have more electrons that can occupy a greater volume of space and therefore have higher entropy.
In 1939, at the age of 20, a man stood 270 cm tall (over 8 1/2 feet) and wore size 37 shoes! The hormonal disorder from which he suffered is known as giantism. Too much of what hormone produced his condition?
Answer:
Somatotropin(Growth Hormone)
Explanation:
-Uncontrolled growth in a person is usually caused by the excessive secretion of growth hormone.
-This hormone is also known as Somatotropin.
-This hormone is produced in the pituitary gland.
what is the formula for tetrabromine decafluoride
Answer:
[tex]Br_{4}F_{10}[/tex]
The prefix "Tetra" implies 4 Bromine atoms. The prefix "Deca" implies 10 fluorine atoms.
Which statements are true? Check all that apply.
Alpha decay emits the same number of protons and neutrons
Beta decay always emits protons.
Beta decay always emits electrons.
Gamma rays are particles of fast-moving matter
Gamma rays are a form of electromagnetic radiation.
DONE
Answer:
A and E
Alpha decay emits the same number of protons and neutrons
Gamma rays are a form of electromagnetic radiation
Explanation:
Just did this one e2020 :)
Answer:
a and e
Explanation:
edge
A gas that has a pressure of 2 atm and
a volume of 10 L. What would be the
new volume if the pressure was
changed to 1 atm?
Answer:
The answer to your question is 20 liters
Explanation:
Data
Pressure 1 = P1 = 2 atm
Volume 1 = V1 = 10 l
Pressure 2 = P2 = 1 atm
Volume 2 = V2 = ?
Process
To solve this problem use Boyle's law
P1V1 = P2V2
-Solve for V2
V2 = P1V1/P2
-Substitution
V2 = (2 x 10)/1
-Simplification
V2 = 20/1
-Result
V2 = 20 l
What is the dropping of a sediment called
Answer:Deposition is the dropping of sediment by wind, water, ice, or gravity.
Explanation:
When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid
Answer:
The dropping of a sediment is called deposition.Define dissolve in your own words
Answer:
Dissolve: to terminate a union of multiple members actively, as by disbanding
Which is the most likely to be reduced?
A. Fe2+
B 7.2+
C. Ni2+
D. Mg2+
Answer:
A. Fe2+
Explanation:
other answer was wrong
[tex]Fe^{2+}[/tex] is the most likely to be reduced. Hence, option A is correct.
What is oxidation?Oxidation: The loss of electrons
Reduction: The gain of electrons
Oxidation number: the charge based on the number of electrons assigned to an atom as compared to the neutral atom.
[tex]Fe^{2+}[/tex] oxidize to [tex]Fe^{3+}[/tex] because removing the electron results in a half-filled d subshell.
Hence, option A is correct.
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We eat food for energy. What is the source of energy for this food chain?
An acid and base will combine to form a new substance with new properties in a _____?
a. physical change
b. chemical reaction
c. distillation
d. concentration
Answer:
chemical reaction... that's because when they combine.. they form a salt and water only
Indicate whether aqueous solutions of the following will contain only ions, only molecules, or mostly molecules and a few ions. You may use answers more than once. Question 5 options: ethanol, C2H5OH, a nonelectrolyte Na2SO4, a strong electrolyte HCN, hydrocyanic acid, a weak electrolyte
Answer:
C2H5OH--- aqueous solution contains mostly molecules
Na2SO4---aqueous solution contains ions
HCN ---aqueous solution contains mostly molecules and a few ions
Explanation:
Only strong electrolytes dissociate completely in solution to form ions. Hence aqueous solutions of strong electrolytes comprises of ions which conduct electricity.
Weak electrolyte aqueous solutions contain mostly molecules since they ionize only to a very small extent in solution.
Nonelectrolytes remain molecular in solution and do not conduct electricity at all.
When dissolved in water, nonelectrolytes like ethanol produce primarily molecules, strong electrolytes like Na2SO4 generate only ions, and weak electrolytes like HCN result in a mix of mostly molecules with a few ions.
Explanation:The type of substances present in a solution can be predicted based on the type of electrolyte. C2H5OH (ethanol), a nonelectrolyte, will mainly form molecules when dissolved in water as it does not ionize. Na2SO4, a strong electrolyte, will fully dissociate in water and produce only ions. HCN (hydrocyanic acid), a weak electrolyte, will produce mostly molecules with a few ions as it only partially ionizes in an aqueous solution.
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Question 2 (1 point)
Which of these pictures is an example of matter? Explain your answer.
Answer:
The kid on the bike.
Explanation:
He has a physical form, whereas the shadow doesn't.
Answer:
the kid on the bicycle
Explanation:
matter is anything that takes up space and a shadow does not physically take up any space
Choose all of the correct statements concerning acids and bases.
Addition of base into the water increase hydronium ion concentration of the solution is a false statement other 4 are correct.
Explanation:
An acid is referred to as substance that is denoting hydrogen ion. A base is referred to as a substance that is accepting hydrogen ions. Certain examples of acids are sulphuric acid, citric acid and certain examples of bases are ammonia as well as bleach. The difference that occur between the acid and the base is due to its pH. Acids have the ability to neutralize the base.Answer: 1, 2 and 5
Explanation:
did usatestprep
Which of the following happens during a chemical change? Check all of the boxes that apply
0 One atom or more changes into atoms of another element.
New substances with different properties are formed.
O Solids, liquids, or gases may form.
0 Reaction mixtures always give off some heat.
0 Reaction mixtures always need to be heated.
Answer:
One atom or more changes into atoms of another element.New subtances with different properties are formed.
Answer:
B. New substances with different properties are formed
C. Solids, Liquids, or gases may form
Explanation:
Edg 2020
A catalytic converter in an automobile uses a palladium or platinum catalyst to convert carbon monoxide gas to carbon dioxide according to the following reaction: 2CO(g) + O2 (g) --> 2CO2(g) A chemist researching the effectiveness of a new catalyst combines a 2.0 : 1.0 mole ratio mixture of carbon monoxide and oxygen gas (respectively) over the catalyst in a 2.45L flask at a total pressure of 740 torr and a temperature of 552 C . When the reaction is complete, the pressure in the flask has dropped to 552 torr. What percentage of the carbon monoxide was converted to carbon dioxide?
Answer:
the fraction of CO reacted is 0.76 or 76.0 %
Explanation:
Step 1: Data given
a new catalyst combines a 2.0 : 1.0 mole ratio mixture of carbon monoxide and oxygen gas
Volume = 2.45 L
Total pressure = 740 torr
Temperature = 552 °C = 825 K
Pressure decreases to 552 torr
Step 2: The balanced equation
2CO(g) + O2 (g) --> 2CO2(g)
Step 3: Calculate the percentage of the CO was converted to CO2
P1/n1 = P2/n2
⇒P1 = the initial pressure = 740 torr
⇒n1 = the initial number of moles = 2.0 moles CO and 1 mol of O2 = 3.0 moles
⇒P2 = the final pressure = 552 torr
⇒n2 = the final number of moles = TO BE DETERMINED
n2 = n1 * P2/P1
n2 =3.0 * 552 torr / 740 torr
n2 = 2.24 moles
Step 4: Calculate total moles of CO
Suppose X = the fraction of CO
final = 2*(x) + 3*(1-x)
2.24 = 2x + 3 - 3x
2.24 = -X + 3
-0.76 = -X
X = 0.76
This means the fraction of CO reacted is 0.76 or 76.0 %
The fraction or the percentage of the carbon monoxide converted to carbon dioxide is 76%.
Given:
Ratio of new catalyst to the mole ratio of carbon dioxide and oxygen = 2:1
Volume = 2.45 L
Temperature = 825 K
Pressure = 740 torr
The reaction is:
2CO(g) + O₂ (g) [tex]\rightarrow[/tex] 2CO₂
From the reaction, the amount of CO converted into carbon dioxide is:
[tex]\dfrac{\text{P}_1}{\text n _1}&=\dfrac{\text{P}_2}{\text n _2}[/tex]
Where,
P₁ = initial pressure
n₁ = number of moles (initial)
P₂ = final pressure
n₂ = final number of moles
Now, calculating the n₂:
[tex]\text n_2 &= \dfrac{\text n_1 \times \text P_2}{\text P_1}[/tex]
[tex]\text n_2 &= \dfrac{3 \times 552}{740}[/tex]
n₂ = 2.24 moles.
Now, the total moles of carbon monoxide is:
2.24 = 2 x Y + 3 x (1 - Y)
2.24 = 2Y + 3 - 3Y
Y = 0.76
Thus, the number of a fraction of CO is 0.76.
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Which 1.0 M solution has the lowest pH?
Answer: nitric acid
Explanation:
The solution with the lowest pH would mean that it is an acid, specifically a strong acid which completely dissociates into ions in aqueous solution. The answer it is nitric acid (HCl) that will have the lowest pH because it is the only strong acid in the group