Sn(no3)2-sn(oh)2-sno-snso4-sn(oh)2-na2[sn(oh)4]-sn(no3)2

Sn(NO3)2 + 2NaOH = Sn(OH)2↓ + 2NaNO3
Sn(OH)2 =t°⇒ SnO + H2O
SnO + H2SO4 = SnSO4 + H2O
SnSO4 + 2NaOH = Sn(OH)2↓ + Na2SO4
Sn(OH)2 + 2NaOH = Na2[Sn(OH)4]
Na2[Sn(OH)4] + 4HNO3 = 2NaNO3 + Sn(NO3)2 + 4H2O

Sn(NO3)2 + 2NaOH -> Sn(OH)2 + 2NaNO3
Sn(OH)2 -> SnO + H2O
SnO + H2SO4 -> SnSO4 + H2O
SnSO4 + 2NaOH -> Sn(OH)2 + Na2SO4
Sn(OH)2 + 2NaOH -> Na2[Sn(OH)4]
Na2[Sn(OH)4] + 4HNO3 -> 2NaNO3 + Sn(NO3)2 + 4H2O