1Substances A and B can each be held easily in separate test tubes, but when both are put in the same test tube, the tube gets so hot it cannot be touched. What causes this? (a) an endothermic reaction (b) an exothermic reaction (c) both endothermic and exothermic reactions (d) an endothermic reaction followed by an exothermic one
2Write the differences between exothermic and endothermic chemical reactions.
3A person is cooking rice by burning wood in a stove. Which reactions here are exothermic and which are endothermic?
4How does the equation show that the reaction of sodium hydroxide with hydrochloric acid is exothermic?
5A candle needs a match to light it. Does that make burning a candle an endothermic reaction? Give a reason.
6What is formed when calcium carbonate is heated? What kind of reaction is it? Write the equation.
7Which exothermic reaction helps keep our body warm? Write its equation.