Question

In the formula for carbon tetrahydride, CH4, the percent composition of all elements is:

Answer 1

C%=12/16*100=3/4*100=75%
H%=25%

Answer 2

Answer:

The percentage composition if carbon tetrahydride is 75% of carbon and 25% of hydrogen.

Explanation:

Molecular mass of carbon tetrahydride = 16 g/mol

Atomic mass of carbon = 12 g/mol

Atomic mass of hydrogen atom = 1 g/mol

Percentage of an element in a compound:

$\frac{\text{Number of atoms of element}\times \text{Atomic mass of element}}{\text{molecular mass of element}}\times 100$

Percentage of carbon:

$\frac{1\times 12 g/mol}{16 g/mol}\times 100=75\%$

Percentage of hydrogen:

$\frac{4\times 1g/mol}{16 g/mol}\times 100=25\%$

The percentage composition if carbon tetrahydride is 75% of carbon and 25% of hydrogen.