[Borek]

"Mixture of NaNO3 and Na2SO4 weights 5.37g and contains 1.61g of sodium. What is the mass percentage of NaNO3 in this mixture?"

Check that the given answer (45%) doesn't give 1.61 g of Na.

[windom626]

To  Hunter2:
So as I have written:

N1*85+N2*142=5.37
N1*62+N2*96=3.76

Yes? Well we get
N1= 0.028 mole of NaNO3
N2= 0.020 mole of Na2SO4

This means - 0.028*85 = 2.38g of NaNO3
and 2.84 g of Na2SO4

This means

2.38 / 5.37 *100% = 44.3%

Which for me is now just a rounding up issue - and it's a correct answer.
Yes?

[Borek]

N1*85+N2*142=5.37

Try with a correct value of 5.71

[Borek]

Why not follow what I wrote.

Because it is an unnecessary detour that in no way makes solving the problem easier nor simpler?

[windom626]

Case closed. Both ways were correct. Thanks for answers. Forever I will remember this.

Did the next excercise, same idea, diffrent compounds I got it right in first aproach.

Thanks!