On analysing an impure sample of sodium chloride, the percentage of chlorine was found to be 45.5. What is the percentage of pure sodium chloride in the sample ?

Explanation

Formula weight of sodium chloride
`= 23 +35.5 = 58.5`
Weight percentage of chlorine in pure sodium chloride `- (35.5)/(58.5) xx 100 = 60.6`
`60.6` parts of Cl (100% pure) has 45.5 parts of Cl Percentage purity of sodium chloride `=(45.5)/(60.6) xx 100 = 75`