Question 1

The characteristic odor of pineapple is due to ethyl butyrate, C6H12O2. A sample of 15.5 g of ethyl butyrate was extracted from some fresh pineapple. How many carbon atoms were obtained from this extraction?

Accepted Answer

Question 2

How many grams are present in 6.5 moles of Cu(NO3) 2?

Accepted Answer

A)   124 g
B)   404 g
C)   1080 g
D)   1200 gE) A) and C)
F) B) and D)

Question 3

Which of the following statements is incorrect concerning BaF2?

Accepted Answer

A)   The total number of fluorine ions present in one formula unit is 2 (6.02 x 1023) .
B)   The total number of fluoride ions present in three moles of BaF2 is equal to 6 (6.02 x 1023) .
C)   The mass of 0.600 moles of BaF2 is 105 grams.
D)   0.600 moles of BaF2 is equivalent to 3.61 x 1023 formula units of BaF2.E) A) and B)
F) A) and C)

Question 4

Nicotine (C10H14N2)  is a byproduct of the tobacco industry and is used as an agricultural insecticide. Calculate the percent composition of each element in nicotine.

Accepted Answer

A)   74.0 % C &ensp; 8.70 % H &ensp; 17.3 % N
B)   83.7 % C &ensp; 4.45 % H &ensp; 11.9 % N
C)   70.2 % C &ensp; 10.5 % H &ensp; 10.3 % N
D)   90.0 % C &ensp; 1.50 % H &ensp; 8.50 % NE) C) and D)
F) None of the above

Question 5

Determine the empirical formula for a compound, a sample of which contains 1.94 1024 atoms C, 6.43 moles of H, and 51.5 g O.

Accepted Answer

C: 1.94 x 1024 atoms C x

= ...

Question 6

What is the molecular formula of a compound that contains 40.0% C, 6.71 % H, and 53.29% O? The molecular mass of this compound is 60.05.

Accepted Answer

A)   C2H4O2
B)   CH2O
C)   C2H3O4
D)   C2H2O4E) C) and D)
F) None of the above

Question 7

How many grams of Cl are present in a 26.0 gram sample of P3N3Cl6?

Accepted Answer

26.0 g P₃N₃Cl₆ x

x

x ...

Question 8

Which of the following compounds has the largest formula mass?

Accepted Answer

A)   BF3
B)   NO2
C)   HCN
D)   CCl4E) A) and B)
F) A) and C)

Question 9

Contrast the two members of each pair in the statements on the left, and then select your response from the response list on the right.
-________(I)  molecules in 3 moles of SO2(II)  molecules in 3 moles of SO3

Accepted Answer

A)   I is greater than II.
B)   I is less than II.
C)   I is equal to II.
D)   It is impossible to make a comparison between I and II.E) B) and D)
F) All of the above

Question 10

What is the mass percent of carbon in dimethyl sulfoxide, C2H6SO?

Accepted Answer

A)   20.6%
B)   60.0%
C)   30.7%
D)   79.8%E) B) and C)
F) A) and D)

Question 11

Avogadro's number of aluminum atoms has a mass equal to ________.

Accepted Answer

A)   6.02 x 1023 g of aluminum
B)   14.01 g of nitrogen
C)   26.98 g of aluminum
D)   6.02 x 10-23 g of calciumE) B) and C)
F) A) and B)

Question 12

Calculate the mass of 1.98 moles of Li2SO3.

Accepted Answer

A)   186
B)   155.37
C)   96.13
D)   316.40E) A) and B)
F) A) and D)

Question 13

How many grams of carbon are present in 26.2 grams of H2CO3?

Accepted Answer

A)   11.60 g
B)   16.8 g
C)   47.3 g
D)   5.07 gE) B) and C)
F) B) and D)

Question 14

Sugar has an empirical formula of CH2O and a molar mass of 180.2 g/mol. If one teaspoon of sugar weighs 3.50 grams, how many moles and molecules of sugar are present?

Accepted Answer

A)   0.117 moles, 7.03 x 1022 molecules
B)   0.0194 moles, 3.24 x 1026 molecules
C)   0.0194 moles, 1.17 x 1022 molecules
D)   0.0583 moles, 3.51 x 1022 moleculesE) A) and B)
F) B) and C)

Question 15

Analysis of an unknown nickel oxide compound indicated that the molar ratio of nickel to oxygen was 0.167 to 0.251, respectively. What is the empirical formula for the compound?

Accepted Answer

A)   Ni3O4
B)   NiO
C)   NiO3
D)   Ni2O3E) All of the above
F) A) and D)

Question 16

The number of atoms contained in 16.0 grams of Mg would be the same as the number of molecules contained in ________ grams of N2O.

Accepted Answer

A)   57.6
B)   29.0
C)   38.0
D)   66.2E) All of the above
F) C) and D)

Question 17

A sample of 15.5 g of caffeine, C8H10N4O2, was extracted from some fresh coffee. How many nitrogen atoms does this sample contain?

Accepted Answer

Question 18

The empirical formula of a compound was determined to be P2O3. The molecular weight of the compound is 220 g/mol. What is the molecular formula of the compound?

Accepted Answer

A)   P2O3
B)   P4O6
C)   P2O5
D)   P4O10E) A) and B)
F) A) and C)

Question 19

Calculate the number of iron atoms in 6.98 x 10-3 grams of iron.

Accepted Answer

A)   9.37 x 1028 atoms
B)   3.92 x 1019 atoms
C)   3.24 x 1023 atoms
D)   7.53 x 1019 atomsE) B) and C)
F) C) and D)

Question 20

What is the molar mass of crotonaldehyde (C4H6O) ?

Accepted Answer

A)   54.1 g/mol
B)   70.1 g/mol
C)   64.0 g/mol
D)   70.0 g/molE) None of the above
F) A) and D)

Exam 9: Chemical Calculations: the Mole Concept and Chemical Formulas

Analysis of an unknown nickel oxide compound indicated that the molar ratio of nickel to oxygen was 0.167 to 0.251, respectively. What is the empirical formula for the compound?

Correct AnswerverifiedShow Answer

What is the mass percent of carbon in dimethyl sulfoxide, C2H6SO?

Correct AnswerverifiedShow Answer

A sample of 15.5 g of caffeine, C8H10N4O2, was extracted from some fresh coffee. How many nitrogen atoms does this sample contain?

Correct AnswerverifiedShow Answer

Which of the following statements is incorrect concerning BaF2?

Correct AnswerverifiedShow Answer

Determine the empirical formula for a compound, a sample of which contains 1.94 1024 atoms C, 6.43 moles of H, and 51.5 g O.

Correct AnswerverifiedC: 1.94 x 1024 atoms C x = ...View AnswerShow Answer

Sugar has an empirical formula of CH2O and a molar mass of 180.2 g/mol. If one teaspoon of sugar weighs 3.50 grams, how many moles and molecules of sugar are present?

Correct AnswerverifiedShow Answer

What is the molecular formula of a compound that contains 40.0% C, 6.71 % H, and 53.29% O? The molecular mass of this compound is 60.05.

Correct AnswerverifiedShow Answer

How many grams of carbon are present in 26.2 grams of H2CO3?

Correct AnswerverifiedShow Answer

How many grams are present in 6.5 moles of Cu(NO3) 2?

Correct AnswerverifiedShow Answer

Avogadro's number of aluminum atoms has a mass equal to ________.

Correct AnswerverifiedShow Answer

Nicotine (C10H14N2) is a byproduct of the tobacco industry and is used as an agricultural insecticide. Calculate the percent composition of each element in nicotine.

Correct AnswerverifiedShow Answer

Calculate the number of iron atoms in 6.98 x 10-3 grams of iron.

Correct AnswerverifiedShow Answer

The empirical formula of a compound was determined to be P2O3. The molecular weight of the compound is 220 g/mol. What is the molecular formula of the compound?

Correct AnswerverifiedShow Answer

The number of atoms contained in 16.0 grams of Mg would be the same as the number of molecules contained in ________ grams of N2O.

Correct AnswerverifiedShow Answer

How many grams of Cl are present in a 26.0 gram sample of P3N3Cl6?

Correct Answerverified26.0 g P3N3Cl6 x x x ...View AnswerShow Answer

What is the molar mass of crotonaldehyde (C4H6O) ?

Correct AnswerverifiedShow Answer

Calculate the mass of 1.98 moles of Li2SO3.

Correct AnswerverifiedShow Answer

Contrast the two members of each pair in the statements on the left, and then select your response from the response list on the right. -________(I) molecules in 3 moles of SO2(II) molecules in 3 moles of SO3

Correct AnswerverifiedShow Answer

Which of the following compounds has the largest formula mass?

Correct AnswerverifiedShow Answer

The characteristic odor of pineapple is due to ethyl butyrate, C6H12O2. A sample of 15.5 g of ethyl butyrate was extracted from some fresh pineapple. How many carbon atoms were obtained from this extraction?

Correct AnswerverifiedShow Answer

Correct Answer
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What is the mass percent of carbon in dimethyl sulfoxide, C₂H₆SO?

Correct Answer
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A sample of 15.5 g of caffeine, C₈H₁₀N₄O₂, was extracted from some fresh coffee. How many nitrogen atoms does this sample contain?

Correct Answer
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Which of the following statements is incorrect concerning BaF₂?

Correct Answer
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Determine the empirical formula for a compound, a sample of which contains 1.94 10²⁴ atoms C, 6.43 moles of H, and 51.5 g O.

Correct Answer
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C: 1.94 x 1024 atoms C x
= ...
View Answer

Sugar has an empirical formula of CH₂O and a molar mass of 180.2 g/mol. If one teaspoon of sugar weighs 3.50 grams, how many moles and molecules of sugar are present?

Correct Answer
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Correct Answer
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How many grams of carbon are present in 26.2 grams of H₂CO₃?

Correct Answer
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How many grams are present in 6.5 moles of Cu(NO₃) ₂?

Correct Answer
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Correct Answer
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Nicotine (C₁₀H₁₄N₂) is a byproduct of the tobacco industry and is used as an agricultural insecticide. Calculate the percent composition of each element in nicotine.

Correct Answer
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Calculate the number of iron atoms in 6.98 x 10^-3 grams of iron.

Correct Answer
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The empirical formula of a compound was determined to be P₂O₃. The molecular weight of the compound is 220 g/mol. What is the molecular formula of the compound?

Correct Answer
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The number of atoms contained in 16.0 grams of Mg would be the same as the number of molecules contained in ________ grams of N₂O.

Correct Answer
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How many grams of Cl are present in a 26.0 gram sample of P₃N₃Cl₆?

Correct Answer
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26.0 g P₃N₃Cl₆ x x x ...
View Answer

What is the molar mass of crotonaldehyde (C₄H₆O) ?

Correct Answer
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Calculate the mass of 1.98 moles of Li₂SO₃.

Correct Answer
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Contrast the two members of each pair in the statements on the left, and then select your response from the response list on the right. -________(I) molecules in 3 moles of SO₂(II) molecules in 3 moles of SO₃

Correct Answer
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Correct Answer
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The characteristic odor of pineapple is due to ethyl butyrate, C₆H₁₂O₂. A sample of 15.5 g of ethyl butyrate was extracted from some fresh pineapple. How many carbon atoms were obtained from this extraction?

Correct Answer
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