Balance the following equations
a)Pb(NO3)2 gives PbO +NO2+O2
b)NH3+CuO gives Cu+N2+H2O
c)NaOH+H2SO4 gives Na2SO4 +H2O
d)Al4C3+H2O gives CH4+Al(OH)3
Which one is correct?
Pb(NO3)2----->PbO+2NO2+O2
or
2Pb(NO3)2----->2PbO+4NO2+O2