# What is the percent composition of H_2S?

Jun 8, 2018

5.88%, 94.12% (2d.p.)

#### Explanation:

percent composition depends on relative atomic mass.

the percentage of component present in a compound is
(relative formula mass of component $\div$ relative formula mass of compound) * 100%

the relative atomic mass of $H$ (hydrogen) is $1$
the relative formula mass of ${H}_{2}$ is $2$.

the relative atomic mass of $S$ (sulphur) is $32$.

$2 + 32 = 34$
the compound ${H}_{2} S$ is known as hydrogen sulphide.

relative formula mass of ${H}_{2}$ $\div$ relative formula mass of ${H}_{2} S$) * 100% = 2/34 * 100%

= 5.88% (2d.p.)

relative formula mass of $S$ $\div$ relative formula mass of ${H}_{2} S$) * 100% = 32/34 * 100%

= 94.12% (2d.p.)

hence, the percentage composition of ${H}_{2}$ and $S$ is 5.88%, 94.12% (2d.p.).