Classify each of the following reactions as a synthesis, decomposition, single-displacement, double-displacement, or combustion reaction:
a. N2(g)+3H2(g)⟶2NH3(g)N2(g)+3H2(g)⟶2NH3(g)
b. 2Li(s)+2H2O(l)⟶2LiOH(aq)+H2(g)2Li(s)+2H2O(l)⟶2LiOH(aq)+H2(g)
c. 2NaNO3(s)⟶2NaNO2(s)+O2(g)2NaNO3(s)⟶2NaNO2(s)+O2(g)
d. 2C6H14(l)+19O2(g)⟶12CO2(g)+14H2O(l)