Answer:
0.50 grams of MgSO₄ are required.
Explanation:
Our solute is MgSO₄.
We determine the 0.20% as a mass percent concentration.
So let's make a rule of three.
Mass percent means the mass of solute in 100g of solution.
In 100 g of solution we have 0.20 g of MgSO₄
Therefore in 250 g of solution we must have (250 . 0.2) / 100 = 0.50 grams of MgSO₄
