Question

How would the percent sulfate in the sample be affected by: a) leaving some precipitate on the stirring rod? c) adding the silver nitrate to the precipitate in the funnel instead of to the                                   washings? (d)   over washing the sample?

Answer 1

Solution :-

a) leaving some precipitate on the stirring rod?

Solution :- If the porecipitate is left on the stirring rod then when we measure the mass of the precipitate formed at the end of reaction would be less than the actual mass of the precipitate formed so the percent of the phosphate would be less than actual present.

c) adding the silver nitrate to the precipitate in the funnel instead of to the                                   washings?

Solution :- Adding the silver nitrate to the precipitate would cause the addition of the mass of the silver in the precipitate so the mass of the precipitat would be higher so it will give the higher percentage of the phosphate.

d)over washing the sample?

Solution :- If the precipitate is overwashed then it may cause some loss of the precipitate during the washing therefore the mass of the precipitate formed would be less than actual mass of the precipitate that is formed so lower mass of precipitate means less percent of the phosphate.