Which of the following is a balanced equation representing the law of conservation of matter?
H2O + MgO → Mg(OH)2
H2SO4 + 2NaOH → Na2SO4 + H2O
CH4 + Cl2 → CH2Cl2 + HCl
Al(OH)3 + H3PO4 → AlPO4 + 2H2O