The purity of gold is measured in karats, with pure gold being 24 karats. other purities of gold are expressed as proportional parts of pure gold. thus 18-karat gold is startfraction 18 over 24 endfraction 18 24, or 75% pure gold; 12-karat gold is startfraction 12 over 24 endfraction 12 24, or 50% pure gold; and so on. how much 2020-karat gold should be mixed with pure gold to obtain 8080 grams of 2222-karat gold? how much 2020-karat gold should be used?

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