Name: Per: ____ Chapter 6 Review

Name: __________________________ Per: ____ Chapter 6 Review 1. Define the following: a. mole b. molar mass c. Avogadro’s number d. empirical formula e. molecular formula 2. Find the molar mass of the following. Include the proper units in your answer. a.

KNO3

d. oxygen gas

b. (NH4)2CO3

e. calcium nitrate

c.

f. lead(II) nitrate

Ag2CrO4

3. Convert the following. a.

_________________

grams  moles  atoms

12.0 g Fe to moles

b. 25.0 g of chlorine gas to moles

c.

0.476 g of (NH4)2SO4 to moles

d. 0.15 moles NaNO3 to grams

e.

0.0280 moles NO2 to grams

f.

0.64 moles aluminum chloride to grams

g. How many atoms are there in 0.00150 moles Zn?

h. If you had 2.50 moles of oxygen gas, what mass of the gas would be in the sample?

i. A 4.07 g sample of Na contains how many atoms of Na?

j. How many molecules of chlorine are there in 16.5 g of chlorine?

k. What is the mass of 100 million atoms of gold?

5. What are the empirical formulas of the following compounds? a. C2H4

____________

d. C3H6

____________

b. C12H4Cl4O2

____________

e. CH4

____________

c. Ag2CrO4

____________

f. P4O10

____________

6. Calculate the empirical formula of a compound that contains 4.20 g of nitrogen and 12.0 g of oxygen.

7. What is the molecular formula of each compound? Empirical Formula

Actual Molar Mass of Compound

CH

78 g/mole

NO2

92 g/mole

Molecular Formula

8. A compound is composed of 7.20 g of carbon, 1.20 g of hydrogen and 9.60 g of oxygen. The molar mass of the compound is 180 g/mole. Determine the empirical and molecular formulas of this compound.

9. What is the % by mass of oxygen in water?

10. What is the % by mass of each element in iron II hydroxide?

11. How many total moles of atoms are present in Ca3(PO4)2 ? ________ 12. How many moles of Hydrogen are represented in C2H4(OH)2? ________ 13. How many moles are in 6.022 x 1023 atoms of silver? ________ 14. How many moles are in 6.022 x 1023 atoms of copper? ________ 15. How many moles are in 6.022 x 1023 atoms of gold? ________ 16. What is the difference between a molecule and an atom?

17. Circle which one(s) contain 6.022 x 1023 atoms: 1 mole O2

2 moles NH3

1 mole NH3

1 mole P

18. Which of the following has the greatest percent by mass of oxygen? (show work, circle answer) H 2O CO2 SO2

19. What is the empirical formula for a compound whose composition is 40. % sulfur and 60. % oxygen by mass?

20. What unit of mass is represented on the periodic table? ______ 21. 1 Nitrogen atom has a mass of _______________ 1 mole of Nitrogen atoms has a mass of _______________