Question

Please help, An impure sample of NaSo4 has a mass of 1.56g.This sample is dissolved and allowed to react with Bacl2 Solution.the resulting precipitate has a mass of 2.15g calculate, (A)the percentage and (B)the mass of Na2So4 in the sample?

Answer 1

Please see the explanation below

Explanation:

The reaction is

`" sodium sulfate "+"barium chloride "rarr "barium sulfate "+" sodium chloride"`

`Na_2SO_4(aq)+BaCl_2(aq) rarrBaSO_4(s)+2NaCl(aq)`

`SO_4^(2-) (aq) + Ba^(2+)(aq)rarr BaSO_4(s)`

Mass of barium sulfate is `=2.15g`

Mass of impure sodium sulfate is `m=1.56g`

Molar mass of `BaSO_4 =233.43g`

Molar mass of `Na_2SO_4=142g`

Mass of pure sodium sulfate is

`=142/233.43*2.15=1.31g`

Percentage of sodium sulfate in the sample is

`=1.31/1.56*100=83.84%`