12.1 STUDY GUIDE Counting Particles of Matter

CIRCLE the letter of the word or phrase that best completes the statement or answers the question.

1. Which of the following quantities is not a mole of the substance?

a. 15.999 g oxygen gas

b. 12.011 g carbon

c. 28.014 g nitrogen gas

d. 4.003 g helium gas

2. The mass of a mole of zinc equals the atomic mass of zinc expressed in:

a. mol

b. kilograms

c. grams

d. number of particles

3. The number of atoms in one mole of sodium metal is:

a. 23

b. 6.02 X 1023

c. 23 ÷ (6.02 X 1023)

d. (6.02 X 1023) ÷ 23

4. The term molecular mass is used only for compounds:

a. containing carbon

b. consisting of ions

c. that are covalent

d. that do not ionize in water

5. A sample of water whose mass is 18 g represents what quantity of water?

a. formula mass

b. molar mass

c. atomic weight

d. atomic mass

6. The formula mass for aluminum chloride is:

a. 62.45 u

b. 6.02 3 1023 u

c. 97.9 u

d. 133.34 u

7. Compared to the number of molecules in a mole of hydrogen gas (H2), the number of molecules in a mole of water (H2O) is:

a. twice as many

b. the same

c. half as many

d. three times as many

8. The mass of an average ruthenium atom is 8.4 times as large as the mass of an average carbon atom. What is the mass of one mole of ruthenium?

a. 8.4 g

b. 8.4 X 6.02 X 1023 g

c. 100.9 g

d. 8.4 X 12 X 6.02 X 1023 g

9. The mass of one molecule of ammonia is its .

a. molecular weight

b. molecular mass

c. formula mass

 

Solve the following problems.

10. Find the number of atoms in each of the following measurements.

 

a. 10.0 g of Al

 

b. 25.9 g of F

 

11. Find the molar mass of each of the following compounds.

 

a. N2O5

 

b. ammonium carbonate

 

12. Express each of the following in grams.

 

a. 0.147 mol of NH4NO3

 

b. 2.60 mol of lithium bromide

 

13. Convert each of the following to its equivalent in moles.

 

a. 17.1 g of H2S

 

b. 2.50 g of copper(II) chloride

 

Answer the following questions.

 

14. How many nitrogen atoms are in 1⁄4 mole of nitrogen gas?

 

 

15. How many moles of oxygen atoms are in 1⁄2 mole of NaIO4?