Complete and balance the equation for the following reaction in which acid are neutralized.
a. HNO3 + Na2O =>
b. HCl + CaCO3 =>
c. H2SO4 + NH3 =>
a. 2 HNO3 + Na2O => 2 NaNO3 + H2O
b. 2 HCl + CaCO3 => CaCl2 + CO2 + H2O
c. H2SO4 + 2 NH3 => (NH4)2SO4