How many moles of methane are in 7.31 x 10^25

121.43 Moles

Explanation: A mole of any element or compound is equal to 6.02 x 10^23 atoms/molecules

The fact that it’s methane doesn’t even matter, all you need is the number of atoms.

So you take 7.31 x 10^25 / 6.02 x 10^23 which equals 121.43 moles.

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