Question

a gaseous compound of carbon and hydrogen contains 80% carbon by weight and the rest is hydrogen the molecular weight of the compound is 30 find its empirical formula and molecular formula

Answer 1

for c 80/12=6.6
for h 20/1=20 now divide 6.6 and 20 by 6.6 to get simple whole no. ratio of C and H which will come 1:3 so emperical frmula is CH3 and its mass is 15
now to calculate n we have 30/15=2
so molecular frmula is ch3 x 2 =C2H6

Answer 2

for c 80/12=6.6

for h 20/1=20 now divide 6.6 and 20 by 6.6 to get simple whole no. ratio of C and H which will come 1:3 so emperical frmula is CH3 and its mass is 15

now to calculate n we have 30/15=2

so molecular formula is ch3× 2 = C2H6