Mr(H3PO4) = 1*3 + 31 + 16*4 = 98
Mr(H2S) = 1*2 + 32 = 34
Mr(SO3) = 32 + 16*3 = 80
Mr(Cu(OH)2) = 63,5 + 16*2 + 1*2 = 97,5
Mr(HF) = 1 + 19 = 20
Mr(P2O5) = 31 *2 + 16*5 = 142
Mr(H3PO4) = 1*3 + 31 + 16*4 = 98
Mr(H2S) = 1*2 + 32 = 34
Mr(SO3) = 32 + 16*3 = 80
Mr(Cu(OH)2) = 63,5 + 16*2 + 1*2 = 97,5
Mr(HF) = 1 + 19 = 20
Mr(P2O5) = 31 *2 + 16*5 = 142