Give a balanced chemical reaaction for the following :
a. Tin is heated with conc `HNO_3`
b. `Pb_3` is treated with nitric acid .
c. Iodine is added to a solution fo stannous chloride .
d. Dil `NHO_2` is slowly reacted with metallic tin.
e. Passing `SiCl_4` vapour over mlten aluminium .
f. Stannous chloride si added to emrcuric chloride .
g. Red lead is treacte will conc ` H_2 SO_4`
h. Red lead is treted with conc `HCl`.

Explanation

a.With conc `HNO_3` hydrated stannic oxide (metastancnic acid ) `(H_2SnO_3)` is formed .
`underset ulbar (Sn+4BO_3^(Θ)+4H^(o+) rarr H_2SnO_3+4NO_2+H_2O)underset (Smn + 3H_2O rarrH_2SnO_3+4H^(o+) +4e^(Θ)) ([NO_3^(Θ) +2H^(o+) +e^(Θ) rarr NO_2 +H_2O] xx4)`
b. `Pb_3O_4` is a mixed oside, `2 PbO. PbO_2` With nitric acide `PbO` is converted into `Pb(NO_3O_2` whereas `PbO_2` remains as such .
`underset or porb_3O_4 + 4HNO_3 rarr PbO_2 + underset (Lead nirate ) (2P b (NO_3)_2 +2H_2O)`
`(2PnO. PnO_2))`
c. Stannous chloride acts as a reducing agebnt and reduces `I_2 rarr 2I^Θ` and itself gets oxidsed to stannic chloride `(Sn^(+4))`.
`(({:(sn^(2+) rarr Sn^(4+)+2e^(Θ)),(I_(2)+2e^(Θ)rarr2I^(Θ)):})/(Sn^(2+)+I_(2) rarr Sn^(4+)+2I^(Θ)))/`
d. Tin reduces dil `NHO_3` to ammonic `(NH_3)`.
`underset ulbar (4Sn + NO_3^(Θ) +10H^(o+) rarr 4Sn^(2+) + [ NH_4]^(o+) +3H_2O)underset (NO_3^(o+) + 10H^(o+) + 83^(Θ) rarr NH_4^(o+) +3 H_2 O) (Sn^(2+) rarrSn^(4+) +2e^(Θ))` .
e. Crystalline silicon si prepard buy passing `SiCl_4` vapoures over molten `Al` .
`3SiCl_4 4 A l rarr 4 A l Cl_3 + 3 Si`
Al being volatinl passes over wbhichle liberated Si dissolves in molten aluminium and separeates as cryatlline silicon .
f. `underset ("chloride") underset ("Stannous") (SnCl_2) + underset ("chloride") underset ("Mercuric") (2HgCl_2) rarr underset ("choride") underset ("Mercurous") (Hg_2Cl_2)`.
`underset ulbar (Sn^(2+) + 2Hg^(2+) rarr Sn^(4+) + Hg_2^(2+)) underset (2e^(Θ) +2Hg^(2+) rarr Hg_2^(2+)) (Sn^(2+) rarr Sn^(4+) +2e^(Θ))`
Stannous chloride acts as a reducing agent and reduces mercuric chloride to mercurous chloride and it self gets reduced to stannic choride .
g. Red lead , `Pb_3O_4` on reacting with conc `H_2SO_4` liberates `O_2` gas ,
`2 P b_3 O_4 + 6SH_2 SO_4 rarr 6PbSO_4 + 6H_2 O +O_2 uarr`
d. red lead, `Pb_3 O_4`, on reacting with conc Hecl, oxidises `Cl^Θ` to `Cl_2` .
`Pb_3O_4 8 HCl rarr 3PbCl_2 + 4 H_2 O + Cl_2 uarr`.