Sodium nitrite is prepared by a reaction of sodium nitrate and carbon: NaNO3 + C → NaNO2 + CO2 Calculate the masses of reactants needed for the preparation of 10 g of NaNO2. Carbon is used in 10% excess. The atomic/molecular masses are: NaNO2= 69.0 g/mol , NaNO3=85.0 g/mol and C=12 g/mol

Answer 1

Keep in mind that the law of conservation mass. That's All.
(Sorry if I seem like a prick)