4. WHAT TEMPERATURE WILL 40 GRAMS OF SODIUM CHLORIDE DISSOLVE IN 100
GRAMS OF WATER?

80∘C .

In fact, you can expect to be able to dissolve no more than 40 g of sodium chloride per 100 g of water at 80∘C . So, at 80∘C , you will ahve an unsaturated solution if you dissolve less than 40 g of sodium chloride, and a saturated solution if you dissolve about 40 g of sodium chloride.

Explanation:

it is the most commonly accepted one