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