The mass % of C in methane CH4 is a) 74.87 b) 7.743 c) 133.6 d) 25.13 €) 92.26 159

a) 74.87 % carbon

Explanation:

Molecular mass of CH₄ is 16.042 g / mole.

Now we divide the following reasoning for 1 mole of methane:

if in 16.042 g of CH₄ there are 12.01 g of carbon

then in 100 g of CH₄ there are X g of carbon

X = (100 * 12.01) / 16.042 = 74.87 % carbon