1. H=2,2/1=2,2 => 5 atomi
I=55,7/127=0,43858 => 1 atom => H5IO6 - acid periodic
O=42,1/16=2,63125 => 6 atomi
124g...............284g
2. P4 + 5O2 = 2P2O5
x=3,1g............7,1g
3. Reactii de combinare:
2H2 + O2 = 2H2O
NH3 + HCl = NH4Cl
Reactii de descompunere:
CaCO3 = CaO + CO2
2CaO = 2Ca + O2
Reactii de substitutie:
H2SO4 + Ca = CaSO4 + H2
2NaCl + Mg = MgCl2 + 2Na
Reactii de schimb:
MgSO4 + Ba(OH)2 = Mg(OH)2 + BaSO4
NaOH + HCl = NaCl + H2O