1. When 0.4 g of impure zinc reacted with an excess of hydrochloric acid, 132 mL of hydrogen was collected over water at 10◦C. The external pressure was 786.6 Torr. What volume
would the dry hydrogen occupy at 1 atm and
298 K?

Answer in Liters

2. What amount of H2 was collected?
Answer in units of mol.

answerspecific gravity;

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o