Considering the equation,
3Na₂SO₄(aq)+2Al(NO₃)₃(aq)------>Al₂(SO₄)₃(s)+6NaNO₃(aq)
As it can be seen from the equation,
2 moles of Al(NO₃)₃ reacts with 3 moles of Na₂SO₄ to give 1 mol of Al₂(SO₄)₃.
Here 690 mL of 2.5 M Al(NO₃)₃=2.5× 690/1000
=1.7 mol of Al(NO₃)₃
As 2 moles of Al(NO₃)₃ give 1 mol of Al₂(SO₄)₃
So 1.7 mol of Al(NO₃)₃ give 1.7/2 mol of Al₂(SO₄)₃
so it will give 0.86 mol of Al₂(SO₄)₃.
Moles=mass given /molar mass
molar mass of Al₂(SO₄)₃= 342.1509 g/mol
Moles= mass given/342.1509
0.86=mass given/342.1509
mass of Al₂(SO₄)₃=295.1 g
so 295.1 g of Al₂(SO₄)₃ will be produced.
