1. Laurie LeBlanc Cuyamaca College
Clicker Questions
Chapter 6 Chemical
Composition
Laurie LeBlanc Cuyamaca College

2. How many moles of Ca are in 3.01 × 1023 atoms of calcium?
Answer: D

3. How many moles of Ca are in 3.01 × 1023 atoms of calcium?
Answer: D

4. Which of the following is correct?
1 mol C = amu C
1 mol C = g C
1 mol C = × 1023 atoms C
Two of the above
All of the above
Answer: D

5. Which of the following is correct?
1 mol C = amu C
1 mol C = g C
1 mol C = × 1023 atoms C
Two of the above
All of the above
Answer: D

6. What is the mass (g) of 1.000 mol of iron?
Answer: E

7. What is the mass (g) of 1.000 mol of iron?
Answer: E

8. What is the molar mass of ammonium nitrate?
g/mol
80.05 g/mol
66.04 g/mol
g/mol
95.23 g/mol
Answer: B

9. What is the molar mass of ammonium nitrate?
g/mol
80.05 g/mol
66.04 g/mol
g/mol
95.23 g/mol
Answer: B

10. How many moles of Pt are in a 455-mg ring of pure platinum?
Answer: C

11. How many moles of Pt are in a 455-mg ring of pure platinum?
Answer: C

12. What is the mass of 4.55 × 1023 copper atoms?
4.55 g
4.31 × 1045 g
1.18 × 10–2 g
6.02 × 1023 g
48.0 g
Answer: E

13. What is the mass of 4.55 × 1023 copper atoms?
4.55 g
4.31 × 1045 g
1.18 × 10–2 g
6.02 × 1023 g
48.0 g
Answer: E

14. How many moles of formula units are in 5.672 g of iron(III) sulfate?
Answer: E

15. How many moles of formula units are in 5.672 g of iron(III) sulfate?
Answer: E

16. How many carbon atoms are in 2.6 μg of graphite (pure carbon)?
Answer: A

17. How many carbon atoms are in 2.6 μg of graphite (pure carbon)?
Answer: A

18. How many moles of formula units are in 5.6 g of lithium nitride?
Answer: C

19. How many moles of formula units are in 5.6 g of lithium nitride?
Answer: C

20. How many formula units are in 2.45 g of chalk (calcium carbonate)?
Answer: B

21. How many formula units are in 2.45 g of chalk (calcium carbonate)?
Answer: B

22. How many moles of oxygen are in 3.45 mol of diphosphorus pentoxide?
Answer: E

23. How many moles of oxygen are in 3.45 mol of diphosphorus pentoxide?
Answer: E

24. How many grams of oxygen are in 40.1 g of calcium hydroxide?
Answer: C

25. How many grams of oxygen are in 40.1 g of calcium hydroxide?
Answer: C

26. If the density of ethanol (C2H5OH) is 0
If the density of ethanol (C2H5OH) is g/cm3, how many molecules are there in 5.50 mL of this substance?
5.67 × 1022 molecules
7.19 × 1022 molecules
6.02 × 1023 molecules
5.50 × 1023 molecules
3.31 × 1024 molecules
Answer: A

27. If the density of ethanol (C2H5OH) is 0
If the density of ethanol (C2H5OH) is g/cm3, how many molecules are there in 5.50 mL of this substance?
5.67 × 1022 molecules
7.19 × 1022 molecules
6.02 × 1023 molecules
5.50 × 1023 molecules
3.31 × 1024 molecules
Answer: A

28. What is the mass of 5.660 mol of dinitrogen tetrahydride?
Answer: D

29. What is the mass of 5.660 mol of dinitrogen tetrahydride?
Answer: D

30. How many moles of molecules are in 1.3 g of liquid bromine?
Answer: A

31. How many moles of molecules are in 1.3 g of liquid bromine?
Answer: A

32. What is the mass of 4.57 × 1021 molecules of ammonia, NH3?
0.457 g
4.57 g
0.129 g
0.137 g g
Answer: C

33. What is the mass of 4.57 × 1021 molecules of ammonia, NH3?
0.457 g
4.57 g
0.129 g
0.137 g g
Answer: C

34. How many moles of sodium are in 5
How many moles of sodium are in 5.29 × 1022 formula units of sodium sulfate?
2 mol
mol
mol
1.06 × 1023 mol
0.176 mol
Answer: C

35. How many moles of sodium are in 5
How many moles of sodium are in 5.29 × 1022 formula units of sodium sulfate?
2 mol
mol
mol
1.06 × 1023 mol
0.176 mol
Answer: C

36. How many moles of oxygen are in one mole of aluminum carbonate?
1 mol O
3 mol O
6 mol O
9 mol O
12 mol O
Answer: D

37. How many moles of oxygen are in one mole of aluminum carbonate?
1 mol O
3 mol O
6 mol O
9 mol O
12 mol O
Answer: D

38. An unknown compound has a molar mass of 118. 10 g/mol
An unknown compound has a molar mass of g/mol. Given the following mass percent composition, calculate the empirical and molecular formulas: 40.7% C, 5.13% H, and 54.2% O.
CH1.5O and C2H3O2
C3H5O3 and C6H10O6
C4H6O4 and C8H12O8
C4H6O4 and C2H3O2
C2H3O2 and C4H6O4
Answer: E

39. An unknown compound has a molar mass of 118. 10 g/mol
An unknown compound has a molar mass of g/mol. Given the following mass percent composition, calculate the empirical and molecular formulas: 40.7% C, 5.13% H, and 54.2% O.
CH1.5O and C2H3O2
C3H5O3 and C6H10O6
C4H6O4 and C8H12O8
C4H6O4 and C2H3O2
C2H3O2 and C4H6O4
Answer: E

40. What is the molar mass of sucrose, C12H22O11?
380.3 g/mol
182.3 g/mol
342.3 g/mol
129.0 g/mol
145.5 g/mol
Answer: C

41. What is the molar mass of sucrose, C12H22O11?
380.3 g/mol
182.3 g/mol
342.3 g/mol
129.0 g/mol
145.5 g/mol
Answer: C

42. What is the mass percentage of oxygen in caffeine, C8H10N4O2?
8.23%
16.5%
28.9%
5.21%
49.5%
Answer: B

43. What is the mass percentage of oxygen in caffeine, C8H10N4O2?
8.23%
16.5%
28.9%
5.21%
49.5%
Answer: B

44. What is the empirical formula of ascorbic acid, C6H8O6, a compound found in citrus fruits?
Answer: C

45. What is the empirical formula of ascorbic acid, C6H8O6, a compound found in citrus fruits?
Answer: C

46. Identify the diatomic molecule that has a mass of 33
Identify the diatomic molecule that has a mass of g and contains moles of molecules. H2 N2 O2 F2
Cl2
Answer: D

47. Identify the diatomic molecule that has a mass of 33
Identify the diatomic molecule that has a mass of g and contains moles of molecules. H2 N2 O2 F2
Cl2
Answer: D

48. Calculate the empirical formula of a 5
Calculate the empirical formula of a 5.85 g sample of an unknown chromium oxide containing 4.00 g of chromium.
Cr2O7
Cr2O4
CrO
CrO1.5
Cr2O3
Answer: E

49. Calculate the empirical formula of a 5
Calculate the empirical formula of a 5.85 g sample of an unknown chromium oxide containing 4.00 g of chromium.
Cr2O7
Cr2O4
CrO
CrO1.5
Cr2O3
Answer: E

50. What is the empirical formula of a compound that contains 14
What is the empirical formula of a compound that contains 14.5% hydrogen and 85.5% carbon by mass? CH
CH2
C2H
C2H3
CH3
Answer: B

51. What is the empirical formula of a compound that contains 14
What is the empirical formula of a compound that contains 14.5% hydrogen and 85.5% carbon by mass? CH
CH2
C2H
C2H3
CH3
Answer: B

52. What is the mass percentage of oxygen in glycerol, C3H8O3?
6.25%
26.08%
54%
52.12%
64.32%
Answer: D

53. What is the mass percentage of oxygen in glycerol, C3H8O3?
6.25%
26.08%
54%
52.12%
64.32%
Answer: D

54. The empirical formula of a compound is found to be CH2O
The empirical formula of a compound is found to be CH2O. If its molar mass is g/mol, what is the molecular formula of the compound?
CH2O
C3H6O3
C6H12O6
C2H4O2
None of the above
Answer: C

55. The empirical formula of a compound is found to be CH2O
The empirical formula of a compound is found to be CH2O. If its molar mass is g/mol, what is the molecular formula of the compound?
CH2O
C3H6O3
C6H12O6
C2H4O2
None of the above
Answer: C

56. A variety of Freon contains 69. 58% chlorine by mass
A variety of Freon contains 69.58% chlorine by mass. How many grams of chlorine are contained in 11.3 g of this substance?
7.86 g
5.35 g
7.863 g g
None of the above
Answer: A

57. A variety of Freon contains 69. 58% chlorine by mass
A variety of Freon contains 69.58% chlorine by mass. How many grams of chlorine are contained in 11.3 g of this substance?
7.86 g
5.35 g
7.863 g g
None of the above
Answer: A

58. What is the mass percentage of oxygen in potassium chlorate?
6.527%
13.06%
19.60%
39.17%
None of the above
Answer: D

59. What is the mass percentage of oxygen in potassium chlorate?
6.527%
13.06%
19.60%
39.17%
None of the above
Answer: D

60. A compound is found to contain 60. 00% C, 4. 48% H, and 35. 53% O
A compound is found to contain 60.00% C, 4.48% H, and 35.53% O. What is its empirical formula?
C9H8O4
C3H2O
C2H2O2
C2H2O
None of the above
Answer: A

61. A compound is found to contain 60. 00% C, 4. 48% H, and 35. 53% O
A compound is found to contain 60.00% C, 4.48% H, and 35.53% O. What is its empirical formula?
C9H8O4
C3H2O
C2H2O2
C2H2O
None of the above
Answer: A