WAEC Chemistry 2019 Paper

- Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products.

- A system of reactants that absorbs heat from the surroundings in an endothermic reaction has a positive ΔH.

- examples of endothermic processes:

• Melting ice cubes.
• Melting solid salts.
• Sublimation of dry ice into carbon dioxide gas.
• Evaporating liquid water.