Question 1

When the following equation is balanced,what is the sum of the coefficients? Al2(SO4) 3 + Ca(OH) 2  →	o→  Al(OH) 3 + CaSO4

Accepted Answer

A)  4
B)  9
C)  8
D)  7
E)  10 F) C) and E)
G) A) and D)

Question 2

A 15-g sample of lithium is reacted with 15 g of fluorine to form lithium fluoride: 2Li + F2 →	o→  2LiF.After the reaction is complete,what will be present?

Accepted Answer

A)  2.16 moles lithium fluoride only
B)  0.789 moles lithium fluoride only
C)  2.16 moles lithium fluoride and 0.395 moles fluorine
D)  0.789 moles lithium fluoride and 1.37 moles lithium
E)  none of these F) None of the above
G) B) and D)

Question 3

If 45.0 g of O2 are mixed with 45.0 g of H2 and the mixture is ignited,what mass of water is produced?

Accepted Answer

A)  45.0 g
B)  50.7 g
C)  79.9 g
D)  25.3 g
E)  90.0 gF) None of the above
G) B) and E)

Question 4

What would be the g Al / mole S ratio for the product of a reaction between aluminum and sulfur?

Accepted Answer

A)  26.98 g Al / mol S
B)  53.96 g Al / mol S
C)  80.94 g Al / mol S
D)  17.99 g Al / mol S
E)  40.47 g Al / mol SF) C) and D)
G) All of the above D

Question 5

Naturally occurring iron contains 5.82%  ,91.66%  ,2.19%  ,and 0.33%  .The respective atomic masses are 53.940 amu,55.935 amu,56.935 amu,and 57.933 amu.Calculate the average atomic mass of iron.

Accepted Answer

The answer of Naturally occurring iron contains 5.82%  ,91.66%...

Question 6

How many of the following are true concerning balanced chemical equations?
I.The number of molecules is conserved.
II.The coefficients for the reactants tell you how much of each reactant you are given.
III.Atoms are neither created nor destroyed.
IV.The coefficients indicate the mass ratios of the substances used.
V.The sum of the coefficients on the reactant side equals the sum of the coefficients on
The product side.

Accepted Answer

A)  1
B)  2
C)  3
D)  4
E)  5F) B) and E)
G) A) and B)

Question 7

What is the sum of the coefficients of the following equation when it is balanced using smallest whole numbers? NaNH2 + NaNO3  →	o→  NaN3 +NaOH + NH3

Accepted Answer

A)  5
B)  6
C)  7
D)  8
E)  9 F) A) and B)
G) A) and D)

Question 8

A hypothetical element consists of two isotopes of masses 69.95 amu and 71.95 amu with abundances of 25.7% and 74.3%,respectively.What is the average atomic mass of this element?

Accepted Answer

A)  70.95 amu
B)  69.95 amu
C)  70.5 amu
D)  71.4 amu
E)  71.95 amuF) A) and B)
G) All of the above

Question 9

Oxides of copper include CuO and Cu2O.You heat 1.51 g of one of these copper oxides in the absence of air and obtain 1.21 g of Cu.
True or false: You must have had CuO.

Accepted Answer

A) True 
 B)False

Question 10

Naturally occurring element X exists in three isotopic forms: X-28 (27.977 amu,92.23% abundance) ,X-29 (28.976 amu,4.67% abundance) ,and X-30 (29.974 amu,3.10% abundance) .What is the identity of element X?

Accepted Answer

A)  Cu
B)  Al
C)  Ni
D)  Si
E)  SrF) B) and D)
G) C) and D)

Question 11

How many grams of H2O will be formed when 32.0 g H2 is mixed with 12.0 g of O2 and allowed to react to form water?

Accepted Answer

A)  13.5 g
B)  286 g
C)  6.8 g
D)  3.4 g
E)  144 gF) B) and D)
G) B) and E)

Question 12

Balanced chemical equations imply which of the following?

Accepted Answer

A)  Numbers of molecules are conserved in chemical change.
B)  Numbers of atoms are conserved in chemical change.
C)  Volume is conserved in chemical change.
D)  A and B
E)  B and CF) All of the above
G) A) and B)

Question 13

Which compound contains the highest percent by mass of hydrogen?

Accepted Answer

A)  HCl
B)  H2O
C)  H2SO4
D)  H2S
E)  HFF) A) and B)
G) A) and C) B

Question 14

You take an aspirin tablet (a compound consisting solely of carbon,hydrogen,and oxygen) with a mass of 1.00 g,burn it in air,and collect 2.20 g of carbon dioxide and 0.400 g water.The molar mass of aspirin is between 170 and 190 g/mol.The molecular formula of aspirin is

Accepted Answer

A)  C6H8O5
B)  C9H8O4
C)  C8H10O5
D)  C10H6O4
E)  none of theseF) A) and C)
G) A) and E) B

Question 15

How many grams of potassium are in 27.8 g of K2CrO7?

Accepted Answer

A)  4.49 g
B)  1.422 g
C)  8.98 g
D)  78.2 g
E)  55.6 gF) None of the above
G) All of the above

Question 16

Give (in order) the correct coefficients to balance the following reaction: H2SnCl6 + H2S  →	o→  SnS2 + HCl

Accepted Answer

A)  1,2,1,6
B)  1,2,2,2
C)  1,1,1,6
D)  6,2,1,1
E)  2,4,2,6 F) A) and E)
G) D) and E)

Question 17

A substance,A2B,has the composition by mass of 60% A and 40% B.What is the composition of AB2 by mass?

Accepted Answer

A)  40% A,60% B
B)  50% A,50% B
C)  27% A,73% B
D)  33% A,67% B
E)  none of theseF) A) and E)
G) A) and B)

Question 18

SO2 reacts with H2S as follows: 2H2S + SO2  →	o→  3S + 2H2O
When 7.50 g of H2S reacts with 12.75 g of SO2,which statement applies?

Accepted Answer

A)  6.38 g of sulfur are formed.
B)  10.6 g of sulfur are formed.
C)  0.0216 moles of H2S remain.
D)  1.13 g of H2S remain.
E)  SO2 is the limiting reagent. F) B) and E)
G) A) and B)

Question 19

What is the mass of 4 atom(s) of copper in grams?

Accepted Answer

A)  254.2 g
B)  2.37  ×	imes×  1021 g
C)  9.57  ×	imes× 10-24 g
D)  6.022  ×	imes×  1023 g
E)  4.22  ×	imes×  10-22 g F) A) and B)
G) B) and C)

Question 20

A chemical reaction has the equation: 2A + B  →	o→  C.Which of the following figures best illustrates a stoichiometric ratio of A and B?
I. 
 II. 
 III.  
IV.

Accepted Answer

A)  I only
B)  II only
C)  III only
D)  IV only
E)  both I and IV F) B) and D)
G) B) and E)

Exam 3: Stoichiometry

When the following equation is balanced,what is the sum of the coefficients? Al₂(SO₄) ₃ + Ca(OH) ₂ $\to$ Al(OH) ₃ + CaSO₄

Correct Answer
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A 15-g sample of lithium is reacted with 15 g of fluorine to form lithium fluoride: 2Li + F₂ $\to$ 2LiF.After the reaction is complete,what will be present?

Correct Answer
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If 45.0 g of O₂ are mixed with 45.0 g of H₂ and the mixture is ignited,what mass of water is produced?

Correct Answer
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What would be the g Al / mole S ratio for the product of a reaction between aluminum and sulfur?

Correct Answer
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D

Naturally occurring iron contains 5.82% ,91.66% ,2.19% ,and 0.33% .The respective atomic masses are 53.940 amu,55.935 amu,56.935 amu,and 57.933 amu.Calculate the average atomic mass of iron.

Correct Answer
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Correct Answer
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What is the sum of the coefficients of the following equation when it is balanced using smallest whole numbers? NaNH₂ + NaNO₃ $\to$ NaN₃ +NaOH + NH₃

Correct Answer
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A hypothetical element consists of two isotopes of masses 69.95 amu and 71.95 amu with abundances of 25.7% and 74.3%,respectively.What is the average atomic mass of this element?

Correct Answer
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Oxides of copper include CuO and Cu₂O.You heat 1.51 g of one of these copper oxides in the absence of air and obtain 1.21 g of Cu. True or false: You must have had CuO.

Correct Answer
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Naturally occurring element X exists in three isotopic forms: X-28 (27.977 amu,92.23% abundance) ,X-29 (28.976 amu,4.67% abundance) ,and X-30 (29.974 amu,3.10% abundance) .What is the identity of element X?

Correct Answer
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How many grams of H₂O will be formed when 32.0 g H₂ is mixed with 12.0 g of O₂ and allowed to react to form water?

Correct Answer
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Balanced chemical equations imply which of the following?

Correct Answer
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Which compound contains the highest percent by mass of hydrogen?

Correct Answer
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B

You take an aspirin tablet (a compound consisting solely of carbon,hydrogen,and oxygen) with a mass of 1.00 g,burn it in air,and collect 2.20 g of carbon dioxide and 0.400 g water.The molar mass of aspirin is between 170 and 190 g/mol.The molecular formula of aspirin is

Correct Answer
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B

How many grams of potassium are in 27.8 g of K₂CrO₇?

Correct Answer
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Give (in order) the correct coefficients to balance the following reaction: H₂SnCl₆ + H₂S $\to$ SnS₂ + HCl

Correct Answer
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A substance,A₂B,has the composition by mass of 60% A and 40% B.What is the composition of AB₂ by mass?

Correct Answer
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SO₂ reacts with H₂S as follows: 2H₂S + SO₂ $\to$ 3S + 2H₂O When 7.50 g of H₂S reacts with 12.75 g of SO₂,which statement applies?

Correct Answer
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What is the mass of 4 atom(s) of copper in grams?

Correct Answer
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Correct Answer
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Exam 3: Stoichiometry

When the following equation is balanced,what is the sum of the coefficients? Al2(SO4) 3 + Ca(OH) 2 →\to→ Al(OH) 3 + CaSO4

Correct AnswerverifiedShow Answer

A 15-g sample of lithium is reacted with 15 g of fluorine to form lithium fluoride: 2Li + F2 →\to→ 2LiF.After the reaction is complete,what will be present?

Correct AnswerverifiedShow Answer

If 45.0 g of O2 are mixed with 45.0 g of H2 and the mixture is ignited,what mass of water is produced?

Correct AnswerverifiedShow Answer

What would be the g Al / mole S ratio for the product of a reaction between aluminum and sulfur?

Correct AnswerverifiedD

Naturally occurring iron contains 5.82% ,91.66% ,2.19% ,and 0.33% .The respective atomic masses are 53.940 amu,55.935 amu,56.935 amu,and 57.933 amu.Calculate the average atomic mass of iron.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

What is the sum of the coefficients of the following equation when it is balanced using smallest whole numbers? NaNH2 + NaNO3 →\to→ NaN3 +NaOH + NH3

Correct AnswerverifiedShow Answer

A hypothetical element consists of two isotopes of masses 69.95 amu and 71.95 amu with abundances of 25.7% and 74.3%,respectively.What is the average atomic mass of this element?

Correct AnswerverifiedShow Answer

Oxides of copper include CuO and Cu2O.You heat 1.51 g of one of these copper oxides in the absence of air and obtain 1.21 g of Cu. True or false: You must have had CuO.

Correct AnswerverifiedShow Answer

Naturally occurring element X exists in three isotopic forms: X-28 (27.977 amu,92.23% abundance) ,X-29 (28.976 amu,4.67% abundance) ,and X-30 (29.974 amu,3.10% abundance) .What is the identity of element X?

Correct AnswerverifiedShow Answer

How many grams of H2O will be formed when 32.0 g H2 is mixed with 12.0 g of O2 and allowed to react to form water?

Correct AnswerverifiedShow Answer

Balanced chemical equations imply which of the following?

Correct AnswerverifiedShow Answer

Which compound contains the highest percent by mass of hydrogen?

Correct AnswerverifiedB

You take an aspirin tablet (a compound consisting solely of carbon,hydrogen,and oxygen) with a mass of 1.00 g,burn it in air,and collect 2.20 g of carbon dioxide and 0.400 g water.The molar mass of aspirin is between 170 and 190 g/mol.The molecular formula of aspirin is

Correct AnswerverifiedB

How many grams of potassium are in 27.8 g of K2CrO7?

Correct AnswerverifiedShow Answer

Give (in order) the correct coefficients to balance the following reaction: H2SnCl6 + H2S →\to→ SnS2 + HCl

Correct AnswerverifiedShow Answer

A substance,A2B,has the composition by mass of 60% A and 40% B.What is the composition of AB2 by mass?

Correct AnswerverifiedShow Answer

SO2 reacts with H2S as follows: 2H2S + SO2 →\to→ 3S + 2H2O When 7.50 g of H2S reacts with 12.75 g of SO2,which statement applies?

Correct AnswerverifiedShow Answer

What is the mass of 4 atom(s) of copper in grams?

Correct AnswerverifiedShow Answer

A chemical reaction has the equation: 2A + B →\to→ C.Which of the following figures best illustrates a stoichiometric ratio of A and B? I. II. III. IV.

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When the following equation is balanced,what is the sum of the coefficients? Al₂(SO₄) ₃ + Ca(OH) ₂ $\to$ Al(OH) ₃ + CaSO₄

Correct Answer
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A 15-g sample of lithium is reacted with 15 g of fluorine to form lithium fluoride: 2Li + F₂ $\to$ 2LiF.After the reaction is complete,what will be present?

Correct Answer
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If 45.0 g of O₂ are mixed with 45.0 g of H₂ and the mixture is ignited,what mass of water is produced?

Correct Answer
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D

Correct Answer
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Correct Answer
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What is the sum of the coefficients of the following equation when it is balanced using smallest whole numbers? NaNH₂ + NaNO₃ $\to$ NaN₃ +NaOH + NH₃

Correct Answer
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Correct Answer
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Oxides of copper include CuO and Cu₂O.You heat 1.51 g of one of these copper oxides in the absence of air and obtain 1.21 g of Cu. True or false: You must have had CuO.

Correct Answer
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Correct Answer
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How many grams of H₂O will be formed when 32.0 g H₂ is mixed with 12.0 g of O₂ and allowed to react to form water?

Correct Answer
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B

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B

How many grams of potassium are in 27.8 g of K₂CrO₇?

Correct Answer
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Give (in order) the correct coefficients to balance the following reaction: H₂SnCl₆ + H₂S $\to$ SnS₂ + HCl

Correct Answer
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A substance,A₂B,has the composition by mass of 60% A and 40% B.What is the composition of AB₂ by mass?

Correct Answer
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SO₂ reacts with H₂S as follows: 2H₂S + SO₂ $\to$ 3S + 2H₂O When 7.50 g of H₂S reacts with 12.75 g of SO₂,which statement applies?

Correct Answer
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Correct Answer
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Correct Answer
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