Chemistry - Gravimetric analysis - activity 3
Gravimetric analysis - activity 3
As part of a chemical analysis exercise a student is supplied with a
sample of sodium sulfate, Na2SO4, which has been uniformly contaminated
with sodium chloride.
The percentage, by mass, of sodium sulfate in the sample is to be
determined by dissolving the contaminated salt in water and using an excess
of barium nitrate Ba(NO3)2(aq) solution to precipitate the sulfate ions as
barium sulfate BaSO4.
The precipitated is collected, washed and dried before weighing.
The student records the following data
mass of contaminated Na2SO4 used = 3.925 g
mass of precipitated collected = 5.803 g
(a) Write a balanced equation for the precipitation reaction.
(b) Calculate the percentage, by mass, of sodium sulfate in the
(c) If the student had been required to determine the percentage, by mass,
of sodium chloride in the sample, would the same experimental technique
have been appropriate?
Answer - part a and b
Answer - part c
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