Calculam masele molare a ambelor subtante: M H2O=2+16=18g/mol , M H2SO4=2+32+4*16=98g/mol a) 18g H2O...........16g O 100G H2O..........xg O =>x=16*100/18=>x=88,88%O b) 98g H2SO4................4*16g O 100g H2SO4.................x g O =>x=64*100/98=>x=65,3%O