Question

how many c atoms are contained in 15.63g of c5h12??

Answer 1

You have to find the mass of 1 mole first. Then you will know what fraction of a mole you are working with

one mole has 5 carbons

your fraction of a mole has ? carbons

Answer 2

5* 12.01+ 12*1.01= 60.05 g/mol
c H
1 mol of C= 60.05g/mol

next step?