Question 1

How many moles of iron are contained in 1.75 kg of iron?

Accepted Answer

A)  3.13 × 10-2
B)  3.13 × 10-4
C)  31.3
D)  3.13 × 104
E)  none of the aboveF) All of the above
G) None of the above

Question 2

One mole of I2 has more atoms in it than one mole of Na.

Accepted Answer

A) True 
 B)False

Question 3

You have 10.0 g each of Na,C,Pb,Cu and Ne.Which contains the smallest number of moles?

Accepted Answer

A)  Na
B)  C
C)  Pb
D)  Cu
E)  NeF) B) and C)
G) C) and E)

Question 4

The molecular formula is equal to the empirical formula multiplied by a whole number integer.

Accepted Answer

A) True 
 B)False

Question 5

What is the correct value for Avogadro's number?

Accepted Answer

A)  6.022 × 1023
B)  6.022 × 1033
C)  6.023 × 1022
D)  6.022 × 102.3
E)  none of the aboveF) None of the above
G) A) and D)

Question 6

A compound composed of only carbon and hydrogen is 25.2% hydrogen by mass.The empirical formula for this compound is:

Accepted Answer

A)  CH 0.25
B)  C3H
C)  CH4
D)  C2H8
E)  none of the aboveF) B) and D)
G) C) and D)

Question 7

If a sample of carbon dioxide contains 3.8 moles of oxygen atoms,how many moles of carbon dioxide are in the sample?

Accepted Answer

A)  1.9
B)  3.8
C)  7.6
D)  11.4
E)  none of the aboveF) A) and E)
G) B) and E)

Question 8

You have 10.0 g each of Na,C,Pb,Cu and Ne.Which contains the largest number of moles?

Accepted Answer

A)  Na
B)  C
C)  Pb
D)  Cu
E)  NeF) B) and D)
G) A) and B)

Question 9

Which of the following contains 9.02 × 1023 atoms?

Accepted Answer

A)  4.00 g H2
B)  9.00 g H2O
C)  28.0 g N2
D)  32.0 g O2
E)  none of the aboveF) B) and C)
G) A) and C)

Question 10

If you have 
Atoms of copper,how many moles of copper do you have?

Accepted Answer

A)  0.250
B)  4.00
C)  0.600
D)  3.00
E)  none of the aboveF) All of the above
G) C) and D)

Question 11

How many hydrogen atoms are in 35.0 grams of hydrogen gas?

Accepted Answer

A)  4.25 × 1025
B)  2.09 × 1025
C)  2.12 × 1025
D)  1.05 × 1025
E)  none of the aboveF) A) and E)
G) B) and D)

Question 12

One mole of potassium sulfate contains:

Accepted Answer

A)  4 moles of oxygen.
B)  2 moles of sulfur.
C)  1 mole of potassium.
D)  3 moles of potassium.
E)  none of the aboveF) B) and C)
G) A) and B)

Question 13

The correct formula for calculating mass percent of X in compound XY is:  
= Mass % X

Accepted Answer

A) True 
 B)False

Question 14

How many atoms are in 1.50 moles of fluorine gas?

Accepted Answer

A)  6.022 × 1023
B)  9.03 × 1023
C)  18.98
D)  1.81 × 1024
E)  none of the aboveF) A) and E)
G) B) and E)

Question 15

The empirical formula mass must be 25.0 if the molecular formula mass is 250 and n = 5.

Accepted Answer

A) True 
 B)False

Question 16

A molecule that has an empirical formula of HO and a molar mass of 34.02 gram must have a molecular formula of H2O2.

Accepted Answer

A) True 
 B)False

Question 17

What is the molar mass of aluminum sulfate?

Accepted Answer

A)  123.0 g/mol
B)  278.0 g/mol
C)  306.2 g/mol
D)  315.2 g/mol
E)  342.2 g/molF) C) and D)
G) A) and E)

Question 18

A 42.7 gram sample of potassium nitrate contains how many grams of potassium?

Accepted Answer

A)  39.1
B)  16.5
C)  21.4
D)  8.54
E)  none of the aboveF) A) and D)
G) B) and D)

Question 19

The mass of one mole of carbon dioxide is ________ g.

Accepted Answer

A)  28.01
B)  384.4
C)  32.00
D)  44.01
E)  none of the aboveF) All of the above
G) A) and E)

Question 20

Vitamin C is known chemically by the name ascorbic acid.Determine the empirical formula of ascorbic acid if it is composed of 40.92% carbon,4.58% hydrogen,and 54.50% oxygen.

Accepted Answer

A)  CHO
B)  CH2O
C)  C2H3O2
D)  C3H4O3
E)  none of the aboveF) B) and C)
G) A) and E)

Exam 6: Chemical Composition

The mass of one mole of carbon dioxide is ________ g.

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How many atoms are in 1.50 moles of fluorine gas?

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A compound composed of only carbon and hydrogen is 25.2% hydrogen by mass.The empirical formula for this compound is:

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Vitamin C is known chemically by the name ascorbic acid.Determine the empirical formula of ascorbic acid if it is composed of 40.92% carbon,4.58% hydrogen,and 54.50% oxygen.

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If you have Atoms of copper,how many moles of copper do you have?

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A 42.7 gram sample of potassium nitrate contains how many grams of potassium?

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How many moles of iron are contained in 1.75 kg of iron?

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A molecule that has an empirical formula of HO and a molar mass of 34.02 gram must have a molecular formula of H2O2.

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The empirical formula mass must be 25.0 if the molecular formula mass is 250 and n = 5.

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You have 10.0 g each of Na,C,Pb,Cu and Ne.Which contains the smallest number of moles?

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What is the molar mass of aluminum sulfate?

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You have 10.0 g each of Na,C,Pb,Cu and Ne.Which contains the largest number of moles?

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How many hydrogen atoms are in 35.0 grams of hydrogen gas?

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The correct formula for calculating mass percent of X in compound XY is: = Mass % X

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One mole of potassium sulfate contains:

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If a sample of carbon dioxide contains 3.8 moles of oxygen atoms,how many moles of carbon dioxide are in the sample?

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One mole of I2 has more atoms in it than one mole of Na.

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What is the correct value for Avogadro's number?

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Which of the following contains 9.02 × 1023 atoms?

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The molecular formula is equal to the empirical formula multiplied by a whole number integer.

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A molecule that has an empirical formula of HO and a molar mass of 34.02 gram must have a molecular formula of H₂O₂.

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One mole of I₂ has more atoms in it than one mole of Na.

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Which of the following contains 9.02 × 10²³atoms?

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