Why is there temp change in chemical reactions

exothermic reaction

a chemical reaction that releases energy to its surroundings

example of exothermic reaction

Combustion

Oxidation

Neutralisation

Everyday examples of exothermic reactions

Hand warmers

Endothermic reactions

Takes in energy from the surroundings so the temp of the surroundings decreases

Examples of endothermic reaction

Thermal decomposition

the reaction between citric acid and sodium hydrogencarbonate

Everyday example of endothermic reaction

Sports injury packs

activation energy

the minimum amount of energy required to start a chemical reaction

label both diagrams

Practical for exothermjc or endothermic reaction

-take measurements of temperature before reaction with thermometer

-take measurements of temperatures at maximum/minimum point

-increase=exothermic

-decrease=endothermic

calculating energy change

energy in-energy out

negative change=exo

positive=endo