Ezekiel learned how to balance chemical equations. Balance the following equations. ^^20a)^^20----NH^+_4(aq)+----OH^-^{}(aq)->----\stackrel{\placeholder{}}{\mathrm{NH}_3(\mathrm{g})+----}H_2O(l) b)----PO^{3+}_4+----MoO^{2-}_4+----H^++------NH^+_4-->---\mleft(_{}NH_4\mright?_3\mleft\lbrack PMo_{12}O_{40}\mright\rbrack+---H_2O ^^20c)^^20------ca^{2+}+-------CO^{2-}_3\rightarrow-----CaCO_3^^20(s)^^20 ^^20d)^^2d^^2d^^2d^^2d^^2d^^2d^^2dAg^++-----_{}_{}_{}_{}_{}_{}_{}_{}_{}_{}_{}_{}_{}Cl^-\cdots\longrightarrow------_{}_{}_{}_{}_{}AgCl