5.1.1 Energy Transfer During Reactions

• Is there more, less, or an equal amount of energy in a chemical reaction at the end compared to the start?

  An equal amount.
• What is an exothermic reaction?

  A reaction which transfers energy to the surroundings, causing the surroundings to increase in temperature.
• What are some examples of exothermic reactions?

  Combustion, neutralisation and many oxidation reactions.
• What are some everyday uses of exothermic reactions?

  Hand warmers and self-heating cans.
• What is an endothermic reaction?

  A reaction which takes in energy from the surroundings, causing the surroundings to decrease in temperature.
• Are exothermic or endothermic reactions more common?

  Exothermic reactions.
• What are some examples of endothermic reactions?

  Thermal decompositions and the reaction between citric acid and sodium hydrogencarbonate.
• What is one everyday use of endothermic reactions?

  Sports injury packs.
• True or false? Energy is stored in chemical bonds.

  True.
• True or false? Different chemical bonds hold different amounts of energy.

  True.
• If the reactant molecules in a reaction have more energy in their chemical bonds than the product molecules, will energy be absorbed or released overall? 

  Released.
• If an exothermic reaction occurs in a closed container, what would happen to the temperature inside the container?

  It would increase.
• If an endothermic reaction occurs in a closed container, what would happen to the temperature inside the container?

  It would decrease.