Find the percent compositions of all of the elements in the following compounds: 1) CuBr2 Cu: Br: 2) NaOH Na: O: H: 3) (NH4)2S N: H: S: 4) N2S2 N: S: Percent Composition Worksheet Solutions Find the percent compositions of all of the elements in the following compounds: 1) CuBr2 Cu: 28.4% Br: 71.6% 2) NaOH Na: 57.5% O: 40.0% H: 2.5% 3) (NH4)2S N: 41.1% H: 11.8% S: 47.1% 4) N2S2 N: 30.4% S: 69.6%