Calculate the percent composition by mass of the following compounds. Round answers to have 3 significant digits. Work the problems in your notes.

Compound	Answer
HgO ____g of Hg ------------------ x 100 ____g of HgO ____g of O ------------------ x 100 ____g of HgO Hg = O =	Interactive popup. Assistance may be required. Check Your Answer HgO Hg = 92.6% O = 7.37%
Na2S Na = S =	Interactive popup. Assistance may be required. Check Your Answer Na2S Na = 58.9% S = 41.1%
(NH4)2S N = H = S =	Interactive popup. Assistance may be required. Check Your Answer (NH4)2S N = 41.1% H = 11.8% S = 47.1%
Sr(NO3)2 Sr = N = O =	Interactive popup. Assistance may be required. Check Your Answer Sr(NO3)2 Sr = 41.3% N = 13.2% O = 45.3%