Answer:
32g
Explanation:
potassium nitrate has solubility of about 67g per 100g of water at 40°C, which means that potassium nitrate solution will contain 67g of dissolved salt for every 100g of water.
since at this temperature, our solution contains 35g of potassium nitrate 100g of water. The solution will be unsaturated because of the less potassium nitrate.
to make saturated solution,
mass of potassuim nitrate = 67g - 35g
= 32g
which means dissolving another 32g of potassium nitrate in solution at 40 °C will make saturated solution.
