Free Printable Mole Conversions, Percent Composition, Formula Determinations

1.

How many moles are in 50 grams of $NaCl$ ? (Molar mass of $NaCl = 58.44 \, \text{g/mol}$ )

a)

0.856 moles

b)

0.923 moles

c)

1.234 moles

d)

1.456 moles

2.

What is the percent composition of carbon in $C_2H_5OH$ ? (Molar mass of $C = 12 \, \text{g/mol}$ , $H = 1 \, \text{g/mol}$ , $O = 16 \, \text{g/mol}$ )

a)

37.5%

b)

46.2%

c)

52.1%

d)

60.0%

3.

Determine the empirical formula of a compound that is 40% sulfur and 60% oxygen by mass.

a)

$SO$

b)

$SO_2$

c)

$SO_3$

d)

$S_2O_5$

4.

A compound has an empirical formula of $CH_2$ and a molar mass of 56 g/mol. What is its molecular formula?

a)

$C_2H_4$

b)

$C_3H_6$

c)

$C_4H_8$

d)

$C_5H_{10}$

5.

How many molecules are in 2 moles of $CO_2$ ?

a)

$1.204 \times 10^{23}$

b)

$6.022 \times 10^{23}$

c)

$1.204 \times 10^{24}$

d)

$1.204 \times 10^{25}$

6.

What is the molar mass of $CaCO_3$ ?

a)

50 g/mol

b)

100 g/mol

c)

150 g/mol

d)

200 g/mol

7.

Convert 10 grams of $H_2$ to moles. (Molar mass of $H_2 = 2 \, \text{g/mol}$ )

a)

2 moles

b)

3 moles

c)

4 moles

d)

5 moles

8.

What is the percent composition of hydrogen in $H_2O$ ?

a)

11.1%

b)

22.2%

c)

33.3%

d)

44.4%

9.

A compound is found to contain 85.7% carbon and 14.3% hydrogen. What is its empirical formula?

a)

$CH$

b)

$CH_2$

c)

$CH_3$

d)

$C_2H_5$

10.

If the empirical formula of a compound is $NH_2$ and its molar mass is 32 g/mol, what is the molecular formula?

a)

$NH_2$

b)

$N_2H_4$

c)

$N_3H_6$

d)

$N_4H_8$

11.

How many atoms are in 3 moles of $Fe$ ?

a)

$1.807\times10^{23}$

b)

$3.612 \times 10^{23}$

c)

$1.807\times10^{24}$

d)

$1.806 \times 10^{25}$

12.

Calculate the molar mass of $C_6H_{12}O_6$ .

a)

180 g/mol

b)

200 g/mol

c)

220 g/mol

d)

240 g/mol

13.

Convert 25 grams of $NaOH$ to moles. (Molar mass of $NaOH = 40 \, \text{g/mol}$ )

a)

0.625 moles

b)

0.750 moles

c)

0.875 moles

d)

1.000 moles

14.

How many particles are in 13.5 grams of Beryllium?

a)

1.5 particles

b)

9 particles

c)

4x10²³ particles

d)

9x10²³ particles

15.

How many formula units are in 9.4 moles of AlCl₃?

a)

5.66

b)

5.66x10²⁴

c)

0.705

d)

1.25x10²³

16.

If a compound has a percent composition of 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen, and its molar mass is 88 g/mol, its molecular formula is (a) .

17.

What is the empirical formula for this compound?

a)

C₆H₂N₆O₃

b)

C₄HN₅O₁₀

c)

CH₃NO₂

d)

CH₅NO₃

18.

Which pair has the same empirical formula?

a)

NaCrO₄ and Na₂Cr₂O₇

b)

C₂H₄O₂ and C₆H₁₂O₆

c)

C₃H₆O₃and C₂H₆O₂

d)

CH₄ and C₂H₆

19.

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

a)

CH₂O

b)

C₂H₄O₂

c)

C₄H₈O₄

d)

C₆H₁₂O₆

20.

Calculate the molar mass of Mg(OH)_2.

a)

42.33 g/mol

b)

41.32 g/mol

c)

82.64 g/mol

d)

58.33 g/mol

21.

How many particles are there in 0.250 mol of Ag?

a)

1.505 x 10^23 particles Ag

b)

6.02 x 10^23 particles Ag

c)

3.01 x 10^23 particles Ag

d)

1.204 x 10^24 particles Ag

22.

How many particles are there in 0.00858 mol NaCl?

a)

5.16 x 10^20 particles NaCl

b)

5.17 x 10^21 particles NaCl

c)

5.15 x 10^22 particles NaCl

d)

5.17 x 10^20 particles NaCl

23.

How many particles are there in 35.4 mol of CO2?

a)

2.13 x 10^23 particles CO2

b)

2.13 x 10^24 particles CO2

c)

2.13 x 10^25 particles CO2

d)

2.13 x 10^22 particles CO2

24.

How many particles are there in 0.425 kmol of N2?

a)

2.56 x 10^23 particles N2

b)

2.56 x 10^24 particles N2

c)

2.56 x 10^25 particles N2

d)

2.56 x 10^26 particles N2

25.

How many moles of Pb are there in 3.25 x 10^20 atoms of Pb?

a)

5.40 x 10^-4 mol Pb

b)

5.40 x 10^-3 mol Pb

c)

5.40 x 10^-5 mol Pb

d)

5.40 x 10^-6 mol Pb

26.

How many grams are in 3.3 x10²³ atoms of N₂I₃

a)

126g

b)

224g

c)

789g

d)

433g

27.

How many atoms of carbon are in 6.00g of carbon?

a)

1.20x10²⁴atoms C

b)

6.02x10²³atoms C

c)

3.01x10²³atoms C

d)

1.50x10²³atoms C

28.

What is the percent composition of Benzene, C₆H₆?

a)

C = 50%
H = 50%

b)

C = 85.7 %
H = 14.3%

c)

C = 92.2%
H = 7.8%

d)

C = 71.9%
H = 28.1%

29.

Determine the empirical formula of a compound that is 36.8% nitrogen and 63.2% oxygen by mass.

a)

$NO$

b)

$N_2O_5$

c)

$NO_2$

d)

$N_2O_3$

30.

Find the percent composition of hydrogen in (NH₄)₂S.

a)

11.8%

b)

41.1%

c)

47.1%

Mole Conversions, Percent Composition, Formula Determinations

Total questions: 30

Worksheet time: 3hrs 30mins

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