Q8-9: A student carried out an experiment to find the solubility of potassium chloride at 30°C. He produced a saturated solution of potassium chloride at 30°C and then heated a known mass of the saturated solution until all the water evaporated. The student obtained the following results:
Mass of saturated potassium chloride solution heated / g
Mass of solid potassium chloride obtained /g
8. The solubility of potassium chloride at 30°C in grams per 100g of water is ……
9. The reliability of the experiment could be improved by ……..
A. Repeating the experiment three times and averaging the results
B. Carrying out the experiment at a range of temperatures
C. Evaporating a larger mass of solution
D. Repeating the experiment with other potassium salts
10. There are three different methods for preparing pure, dry samples of a salt:
1. Adding an excess insoluble solid to acid
2. Adding alkali to acid
Which method is most suitable to prepare each of the salts in the table below?