M HgO = 201+16 = 217 g/mol
2*217 g HgO.......1 mol O2
x........................2,5 moli O2
x = 1085 g HgO
n = m/M = 1085/217 = 5 moli HgO
M KClO3 = 39+35,5+3*16 = 122,5 g/mol
V c.n. = 22,4 l
2*122,5 g KClO3.........3*22,4 l O2
4,9 g KClO3.......................x
x = 1,344 l O2