Percentage Composition, Empirical and Molecular Formula

1 g of a mixture of sodium chloride and sodium nitrate is dissolved in water. On adding silver nitrate solution, 1.435 g of AgCl is precipitated.

\[\ce{AgNO3_{( aq)} + NaCl_{( aq)}-> AgCl_{(s)} + NaNO3}\]

Calculate the precentage of NaCl in the mixture.

Find the empirical formula of the compounds with the following percentage composition:

Pb = 62.5%, N = 8.5%, O = 29.0%

A sample of ammonium nitrate when heated yields 8.96 litres of steam (measure at STP).

\[\ce{NH4NO3 -> N2O + 2H2O}\]

1. What volume of dinitrogen oxide is produced at the same time as 8.96 litres of steam?
2. What mass of ammonium nitrate should be heated to produce 8.96 litres of steam? (Relative molecular mass of ammonium nitrate is 80).
3. Determine the percentage of oxygen in ammonium nitrate (O = 16).

Commercial sodium hydroxide weighing 30 g has some sodium chloride in it. The mixture on dissolving in water and subsequent treatment with excess silver nitrate solution formed a precipitate weighing 14.3 g. What is the percentage of sodium chloride in the commercial sample of sodium hydroxide? The equation for the reaction is

\[\ce{NaCl + AgNO3 -> AgCl + NaNO3}\]

[Relative molecular mass of NaCl = 58, AgCI = 143]

Find the percentage of oxygen in magnesium nitrate crystals [Mg(NO₃).6H₂O].

Calculate the percentage of nitrogen and oxygen in ammonium nitrate. [Relative molecular mass of ammonium nitrate is 80, H = 1, N = 14, O = 16].

Urea is a very important nitrogenous fertilizer. Its formula is CON₂H₄. Calculate the percentage of carbon in urea. (C = 12, O = 16, N = 14 and H = 1)

Find the percentage of water of crystallisation in CuSO₄.5H₂O. (At. Mass Cu = 64, H = 1, O = 16, S = 32)