Chemistry (7th Edition)

(a) $SiCl_4 + 2H_2O -- \gt SiO_2 + 4HCl$ (b) $P_4O_{10} + 6H_2O -- \gt 4H_3PO_4$ (c) $CaCN_2 + 3H_2O -- \gt CaCO_3 + 2NH_3$ (d) $3NO_2 + H_2O -- \gt 2HNO_3 + NO$
(a) Balance the $Cl$ compounds on each side: $SiCl_4 + H_2O -- \gt SiO_2 + 4HCl$ Balance the hydrogen compounds: $SiCl_4 + 2H_2O -- \gt SiO_2 + 4HCl$ (b) Balance the $P$ compounds on each side: $P_4O_{10} + H_2O -- \gt 4H_3PO_4$ Balance the $H$ compounds on each side: $P_4O_{10} + 6H_2O -- \gt 4H_3PO_4$ (c) Balance the $N$ compounds on each side: $CaCN_2 + H_2O -- \gt CaCO_3 + 2NH_3$ Balance the $H$ compounds: $CaCN_2 + 3H_2O -- \gt CaCO_3 + 2NH_3$ (d) Balance the $H$ compounds on each side: $NO_2 + H_2O -- \gt 2HNO_3 + NO$ To balance the equation, we just need 2 more $N$ and 4 more oxygens on the left side; therefore, we can just add 2 more $NO_2$. $3NO_2 + H_2O -- \gt 2HNO_3 + NO$