Types of Reactions Science 10

Chemical Reactions can be: Exothermic: Reactions that release energy Example: A chemical explosion Endothermic: A reaction that needs energy in order for the reaction to take place. Example: Cooking a pancake over a hot stove.

To break chemical bonds, energy is needed. Example: thermal energy + 2H2O → 2H2 + O2 There is always a release of energy when reactants are added together. Example: 2H2 + O2 → 2H2O + thermal energy

Examples … vaporization of water condensation of water ice melting rusting of iron photosynthesis cellular respiration cooking food an explosion Endothermic Exothermic Examples …

Endothermique ou Exothermique? 1. Melting ice endothermic 2. A mixture of H2 and Cl2 that explode after they are mixed together Exothermic 3. Na + Cl2 → NaCl + thermal energy exothermic 4. thermal energy + H2O → H2 + O2

Indicate whether each of the following are exothermic or endothermic reactions.   Melting Ice Sulphuric acid added to water increases the temperature of the solution.    A mixture of hydrogen and chlorine gas explodes if it is mixed together.   Cooking a pancake over a hot stove.   Thermal energy   + NO2   →  N2  +  O2       Na  +  Cl2  →  NaCl  +  thermal energy