HSC Chemistry 2016, multiple choice paper (1 Viewer)

[Diamondhead74512]

Hello!

I was wondering if someone could kindly solve Q19 from the 2016 hsc chemistry paper

Excess barium nitrate solution is added to 200 mL of 0.200 mol L–1 sodium sulfate.What is the mass of the solid formed?
(A) 4.65 g
(B) 8.69 g
(C) 9.33 g
(D) 31.5 g

The answer is (C) Could someone please show the working out?

 

[jazz519]

First write an equation
ba(no3)2 + na2so4 -----> baso4 + 2nano3

the solid is baso4 from solubility rules

n(na2so4) = cv = 0.200*0.200 = 0.04 moles

n(baso4) = 0.04 moles (1:1 mole ratio)

m(baso4)=n*M=0.04*233.38=9.3352 grams