An impure sample of sodium chloride which weighed 1.2 g gave on treatment with excess of silver nitrate solution 2.4g of silver chloride as precipitate.Calculate the percentage purity of the sample

An impure sample of sodium chloride which weighed 1.2 g gave on treatm

1.	An impure sample of sodium chloride which weighed 1.2 g gave on treatment with excess of silver nitrate solution 2.4g of silver chloride as precipitate.Calculate the percentage purity of the sample
Answer» Solution :The double DECOMPOSITION reaction involved is: `NaCl(aq) + AgNO_(3)(aq) to NaNO_(3)(aq) + AgCl(s)` Mass of NaCl taken = 0.989 g Mass of AgCl formed = 2.42 g Using the relation `("Mass of NaCl")/("Mass of AgCl") = ("EQUIVALENT WEIGHT of NaCl")/("Equivalent weight of AgCl") =("Eq. weight of Na + Eq. weight of Cl")/("Eq. weight of Ag + Eq. weight of Cl")` and substituting the values, we GET `0.989/2.42 = ("Eq. mass of Na" + 35.5)/(108 + 35.5)` `=(0.989/2.43 xx 143.5) - 35.5 = 58.4- 35.5 = 22.9`