What is the percent composition of #H_2S#?

1 Answer
Apr 2, 2016

#5.92% H#, #94.08% S#

Explanation:

Total mass of a compound is found by adding up the mass of all the atoms. Using mass numbers from the RSC periodic table, the total mass of the compound #H_2S# is

#2 * 1.008gmol^-1 + 1 * 32.06gmol^-1 = 34.076gmol^-1#

Percentage mass of an element in a compound is given by

#M_e/M_t * 100%#

where #M_e# is the mass of all the atoms of the element and #M_t# is the total mass of the compound.

Percentage mass of hydrogen therefore is

#(2.016gmol^-1)/(34.076gmol^-1) * 100% = 5.92%#

And, likewise, percentage mass of sulfur is

#(32.06gmol^-1)/(34.076gmol^-1) * 100% = 94.08%#