A sample of 29.344 g of dinitrogen monoxide reacts with an excess of oxygen to form 61.343 g of dinitrogen tetroxide. According to the Law of Conservation of Mass, the amount of oxygen gas that reacted with the nitrogen-containing gas is: 90.687 g O, 2

47.997 g O2
47.997 g O, 2

31.999 g O, 2

2.090 g O, 2

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