×100 In a molecular of CCl4 (carbon tetrachloride), =1C+4‌Cl atoms are present. Atomic mass of C=12.01,Cl=35.5 Molecular mass of CCl4=154 Mass % of C=
12.01
154
×100=7.79 Mass % of Cl=
4(35.5)
154
×100 =
142
154
×100=92.7 So, mass \% of C and Cl is approximately cqual to 7.84 and 92.80 respectively.