Exothermic and Endothermic Reactions: Hot and Cold Packs. A small amount of water is added to zip-loc baggies containing either calcium chloride dihydrate or ammonium chloride. The resultant solution becomes hot or cold respectively. The bags are passed around the room so that students can directly sense the temperature changes.

sodium hydroxide (NaOH) dissolve in water. Write equations and prepare sketches showing the form in which each of these compounds is present in its respective solution. Solution Methanol, CH 3OH, dissolves in water in all proportions, interacting via hydrogen bonding. Methanol: CH OH( ) H O( ) CH OH( ) 3 2 3 l l aq

Byju's Answer Standard IX Chemistry Physical and Chemical changes Is dissolutio. Question Is dissolution of copper sulphate in water a chemical change? Justify your answer. Solution When Copper sulphate is dissolved in water, it simply dissociates into ions of copper and sulphate in the solution.