Question

The number of hydrogen atoms in 80 a.m.u. of methane is ____

Answer 1

Weight percentage of hydrogen in methane is

= (4*100)/16 = 25%

Percentage weight of hydrogen in 80 amu of methane is

= (25*80)/100 = 20 amu

Thus, there will be 20 hydrogen atoms in 80 amu of methane.

Answer 2

Given: 80 amu of methane.

To find: We have to find the number of hydrogen atoms.

Solution:

To determine the number of hydrogen atoms we have to follow the below steps-

The chemical formula of methane is $CH_4$.

The atomic mass of carbon is 12 and H is 1.

Thus the molecular mass of methane is 12×1+4=16 amu.

16 amu of methane has $4×6.022×10^{23}=24.088×10^{23}$ number of hydrogen atoms.

80 amu of methane has $80/16×24.088×10^{23}=120.44×10^{23}$ number of hydrogen atoms.

80 amu of methane has $120.44×10^{23}$ number of hydrogen atoms.