How can I find the percent composition of (NH4)2S?

Question

Wyatt Atkins · Accepted Answer

You calculate the mass of each atom in a formula unit, divide by the formula mass, and multiply by 100 %.

See What does percent composition mean?

For calculation purposes, we can write the formula of (NH₄)₂S as N₂H₈S.

Mass of N = 2 atoms N × #(14.01"u")/(1"atom N")# = 28.02 u

Mass of H = 8 atoms H × #(1.008"u")/(1"atom H")# = 8.064 u

Mass of S = 1 atom S × #(32.06"u")/(1"atom S")# = 32.06 u

Mass of (NH₄)₂S = (28.01 + 8.064 + 32.06) u = 68.144 u

% S =#(28.02"u")/(68.144"u")# × 100 % = 41.12 %

% H =#(8.064"u")/(68.144"u")# × 100 % = 11.83 %

% N =#(32.06"u")/(68.144"u")# × 100 % = 47.05 %

Xavier Avery · Answer

undefined To find the percent composition of (NH₄)₂S, you need to calculate the molar mass of the compound first. Then, divide the molar mass of each element by the molar mass of the entire compound, and multiply by 100 to find the percent composition of each element. For (NH₄)₂S, nitrogen (N) has a molar mass of approximately 14.01 g/mol, hydrogen (H) has a molar mass of approximately 1.01 g/mol, and sulfur (S) has a molar mass of approximately 32.07 g/mol. The total molar mass of (NH₄)₂S is the sum of the molar masses of all the atoms in the compound.