Me with these

4. calculate the molar masses of the following chemicals. be sure to show all work and indicate your final answer with a circle or box.
a. cl2

b. becl2

c. (nh4)2so4

d. k2(no3)

5. given the number of moles of each find the number of grams of each.

c. 21.5 moles of sodium carbonate

d. 6 moles of hexane c6h6

6. given the mass of each substance in grams find the number of moles of each:
a. 10 grams of hf

b. 1.2 grams of fecl3

c. 12.7 grams of co2