Balance the following

Cl2 + NaBr -> ?
CaCO3 -> ?
Zn + HCl -> ?
Ca(OH)2 -> ?
H3PO4 + KOH -> ?
AgNO3 + Ha -> ?
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Balanced equations have equal numbers of atoms on each side. The net charge also balances. The number of molecules does not have to be equal.

Cl2 + 2NaBr -> Br2 + 2 NaCl (REDOX : Bromine is reduced by Chlorine)

CaCO3 ->Ca(+2) + CO3(-2) (not very soluble, but these ions form)

Zn + 2HCl ->ZnCl2 + H2 (classic metal + acid = salt and gas)

Ca(OH)2 ->Ca(+2) + 2OH(-) (not very soluble, but these ions form)

(acid + base = salt and water)
H3PO4 + KOH ->KH2PO4 + H2O (Potassium dihydrogen phosphate formed)
H3PO4 + 2KOH ->K2HPO4 + 2H2O (Potassium hydrogen phosphate formed)
H3PO4 + 3KOH ->K3PO4 + 3H2O (Potassium phosphate formed)

AgNO3 + Ha ->Aga + HNO3 ("Ha" is some kind of acid)

You might want to include those silly subscripts like "(g)", "(s)" and "(aq)" which chemnistry teachers are so fond of. Working chemists never use them.