1.
2H2O -> 2H2 + O2
mH2O = 54g
mO2 = ?
Mh2o = 18g/mol
Mo2 = 32g/mol
36g H2O —- 32g O2
54g H2O —- k g O2
k = 48g O2
2.
Mg + 2HCL = MgCl2 + H2
Mmg = 24g/mol
Mhcl = 36,5g/mol
Mmgcl2 = 24 + 71 = 95g/mol
Mh2 = 2g/mol
mMgCl2 = 10g
24g Mg —- 95g MgCl2
x g Mg —- 10g MgCl2
x = 2,53g Mg
3.
Cl2 + 2Na = 2NaCl
mNa = 6,9g
mNaCl = ?
Mna = 23 g/mol
Mnacl = 23 + 35,5 = 58,5 g/mol
46g Na —- 58,5g NaCl
6,9g Na —- y g NaCl
y = 8,76g Na
4.
2Fe + 6HCl = 2FeCl3 + 3H2
mFe = ?
mFeCl3 = 25g
Mfe = 56g
Mfecl3 = 56 + 35,5*3 = 56+106,5 = 162,5g
112g Fe —- 325g FeCl3
z g Fe —- 25g FeCl3
z = 8,62g Fe