help plz 3 questions!! only answer if ur 100% sure:) thank u!!!

5. One of your experiments will be a "calibration" where known amount of warm water with a specified temperature are added to the ambient water in the calorimeter. Why do you think that you have to perform this step? You'll have to subtract the heat absorbed by the calorimeter in the other experiments. You must establish the shape of the graph before performing the other experiments. The water you add emulates the solids you'll add later and provides important information on how they will dissolve. 6. You know that heating a liquid decreases the solubility of a gas. Based on that information alone, what sort of reaction do you think that the dissolution of a gas is? exothermic endothermic insufficient information to tell 7. Dissolution can be viewed as taking three steps. 1. Breaking solutesolute attractions (endothermic), e.g. ionic bonds 2 . Breaking solventsolvent bonds (endothermic), e.g. hydrogen bonds 3 . Forming solventsolute bonds (exothermic) Do you think that hard solutes are more likely to have exothermic or endothermic heats of dissolution? exothermic endothermic makes no difference