1. What is the molar mass of calcium phosphate?
g/mole
g/mole
g/mole
g/mole
g/mole
Answer: a

2. What is the molar mass of calcium phosphate?
g/mole
g/mole
g/mole
g/mole
g/mole
Answer: a

3. Which sample represents the greatest number of moles?
44.01 g CO2
1.0 moles C3H8
6.022 x 1023 molecules C4H10
18.02 g H2O
All of the samples have the same number of moles.
Answer: e

4. Which sample represents the greatest number of moles?
44.01 g CO2
1.0 moles C3H8
6.022 x 1023 molecules C4H10
18.02 g H2O
All of the sample have the same number of moles.
Answer: e

5. Which of the following contains the largest number of molecules?
10.0 g CH4
10.0 g C2H6
10.0 g SO2
10.0 g Xe
Answer: a

6. Which of the following contains the largest number of molecules?
10.0 g CH4
10.0 g C2H6
10.0 g SO2
10.0 g Xe
Answer: a

7. Which of the following contains the largest mass percent hydrogen?
10.0 g CH4
10.0 g C2H6
10.0 g H2O
10.0 g H2S
Answer: a

8. Which of the following contains the largest mass percent hydrogen?
10.0 g CH4
10.0 g C2H6
10.0 g H2O
10.0 g H2S
Answer: a

9. Calculate the number of carbon atoms in 25
Calculate the number of carbon atoms in 25.0 grams of isopropyl alcohol (C3H8O).
1.25 C atoms
15.0 C atoms
2.51 x 1023 C atoms
7.52 x 1023 C atoms
2.07 x 10–24 C atoms
Answer: d

10. Calculate the number of carbon atoms in 25
Calculate the number of carbon atoms in 25.0 grams of isopropyl alcohol (C3H8O).
1.25 C atoms
15.0 C atoms
2.51 x 1023 C atoms
7.52 x 1023 C atoms
2.07 x 10–24 C atoms
Answer: d

11. An unknown compound contains the following percents by mass: C: 60
An unknown compound contains the following percents by mass: C: 60.86%, H: 5.83%, O: 23.16%, and N: 10.14%. Find the empirical formula.
C6H8O2N2
C7H8O2N
C6H8O2N
C8H8O2N
C8H8ON
Answer: b

12. An unknown compound contains the following percents by mass: C: 60
An unknown compound contains the following percents by mass: C: 60.86%, H: 5.83%, O: 23.16%, and N: 10.14%. Find the empirical formula.
C6H8O2N2
C7H8O2N
C6H8O2N
C8H8O2N
C8H8ON
Answer: b

13. What is the empirical formula of a compound containing C, H, and O if combustion of 3.69 g of the compound yields 5.40 g of CO2 and g of H2O?
CH3O
C2H3O
CHO
C2H3O2
CH2O
Answer: e

14. What is the empirical formula of a compound containing C, H, and O if combustion of 3.69 g of the compound yields 5.40 g of CO2 and g of H2O?
CH3O
C2H3O
CHO
C2H3O2
CH2O
Answer: e

15. What are the coefficients for the decomposition of nitroglycerin?
__ C3H5N3O9  __ N2 + __ CO2 + __ H2O + __ O2
2,3,6,2,1
2,3,6,5,1
4,6,12,10,12
4,3,12,10,1
4,6,12,10,1
Answer: e

16. What are the coefficients for the decomposition of nitroglycerin?
__ C3H5N3O9  __ N2 + __ CO2 + __ H2O + __ O2
2,3,6,2,1
2,3,6,5,1
4,6,12,10,12
4,3,12,10,1
4,6,12,10,1
Answer: e