Homework #19

2CAS #13-17


13. a. 6 moles
      b. 5 moles
      c. 5 moles

14. a. 1 mole

      b. 621 g 
      c. 28 g 
      d. 415 g

15. The percent of the oxygen atoms is 67%, because oxygen's molar mass is 32 and carbon's molar mass is 12 in this molecule. Therefore, the percent oxygen by mass 32g/44g x 100%, or 73%. 

16. 

a. 

molar masses: Ag -216g and S -32g
87% silver by mass
b.
molar masses: Al -54g and O -48g
53% aluminum by mass
c. 
molar masses: Ca-40g; C-12g; O-48g
40% calcium by mass

17. 

a. 68%

b. 10%

c. 6.8%