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When an acid reacts with a base, a salt is produced.

NaOH + HNO3 = NaNO3 + H2O

To calculate the percentage composition of NaNO3, find the molecular mass of NaNO3

23 (Na) +12 (N) +16*3 (O3) = 83

The molecular weight of NaNO3 = 83

83 – 100%

23 (Na) – X%

X = 23 * 100 /83 = 27.7% of Na

83 – 100%

12 (N) – X %

X = 12 * 100/83 = 14.5% of N

83 – 100%

48 (O) – X %

X = 48 * 100/83 = 57.8% of O

Some salts are more soluble in water; some are less soluble or not soluble at all. When a non-soluble salt is produced as a result of an acid and base reaction, a precipitate is formed.

Ca (OH) 2 + H2CO3 = CaCO3 +2H2O

CaCO3 is not soluble in water. A white precipitate is formed.

Salts may react with each other and new salts are produced: