J.R. S. answered 06/02/22
Ph.D. University Professor with 10+ years Tutoring Experience
For this problem, you should have been provided a solubility curve. It usually has the solubility of several salts as a function of temperature. So, you need to find the curve for KCl (potassium chloride), and read the answer off of that curve. The solubility (y axis) is usually given as grams / 100 mls. Here you 65 g / 150 ml which equates to approximately 43 g / 100 ml. Find that on the y axis and read the corresponding temperature off the x axis.
The value I get on the curves that I found is approximately 60ºC.