Răspuns:
ro=m/v---> m= 1,428g/lx720= 1028,l6gO2
Vaer= 100x720/20l=3600 l
miu,MgO= 40g/mol
miu,MgCl2= 95g/mol
miu,H2O=18g/mol
1mol.......1mol.........1mol sau, in grame
2HCl + MgO----> MgCl2+ H2O
40g............95g.........18g
. 32g.................x.............y
x=76gMgCl2
y=14,4gH2O
Explicație: