A scientist wanted to determine how temperature effects the solubility of KNO3 in 100 g. of water. Solid KNO3 was added to a beaker filled with 100g of water at 10oC. The beaker was stirred at the same rate until all the solid dissolved. The total amount of KNO3 that was dissolved was 22 g. The scientist repeated the experiment with 100 g. of water at 30oC and 50oC. When the temperature was 30oC, 48 g. of KNO3 was dissolved and when the temperature of the water was 50oC, 84 g. of KNO3 was dissolved. Which of the following is the best conclusion for this experiment?