Question

Электронный ) na+h2o => naoh+h2 ; pb(no3)2 => 2pbo+no2+o2

Answer 1

2Na + 2H₂O = 2NaOH + H₂
Баланс
$\left. \begin{array}{r} \mathrm{Na^{0}-e^{-}\to Na^{+}} \\ \mathrm{2H^{+}+2e^{-}\to H_{2}^{0}} \end{array} \right|2 \left| \begin{array}{l} \mathrm{2-reducing\;agent} \\ \mathrm{1-oxidizing\;agent} \end{array} \right.$.

2Pb(NO₃)₂ = 2PbO + 4NO₂ + O₂
Баланс
$\left. \begin{array}{r} \mathrm{2O^{-2}-4e^{-}\to O_{2}^{0}} \\ \mathrm{N^{+5}+e^{-}\to N^{+4}} \end{array} \right|4 \left| \begin{array}{l} \mathrm{1-reducing\;agent} \\ \mathrm{4-oxidizing\;agent} \end{array} \right.$.