a student was asked to determine the purity of a contaminated sample of ammonium chloride.a sample of 5g was warmed with 100cm^3 of Noah.

a student was asked to determine the purity of a contaminated sample of ammonium chloride.a sample of 5g was warmed with 100cm^3 of Noah.after all the ammonia was driven off,the excess Noah required 25cm^3 of 0.5mol/dm^3 sulfuric acid for neutralization.calculate the purity of the ammonium chloride in the sample.