Answer:
55 g
Explanation:
First, we have to look for the solubility of KNO₃ at 60°C, considering that the solubility is the maximum amount of solute that can be dissolved in 100 grams of solvent, that is, the concentration of a saturated solution.
The solubility of KNO₃ at 60°C is 110.0 g of KNO₃ per 100 g of water. The mass of KNO₃ that must be dissolved in 50 g of water to make a saturated solution is:
50 g H₂O × (110.0 g KNO₃/100 g H₂O) = 55 g KNO₃
