Energetics

• What is the focus of the chapter on energetics in physical chemistry?

  It explores examples of reactions that produce heat and those that require constant heating.
• How are exothermic and endothermic reactions defined?

  Exothermic reactions release heat, while endothermic reactions absorb heat.
• What are the learning objectives related to calorimetry experiments?

  • Describe simple calorimetry experiments for combustion, displacement, dissolving, and neutralisation.
  • Calculate heat energy change using $Q =$$mc\Delta T$.
• What is calcium oxide commonly known as?

  Quicklime
• What happens when water is added to calcium oxide?

  It produces calcium hydroxide and releases enough heat to boil the water.
• What is the chemical equation for calcium oxide reacting with water?

  \text{CaO(s) + H}_2\text{O(l) } \rightarrow \text{Ca(OH)}_2\text{(s)}
• What happens to the chemical energy in an exothermic reaction?

  It is converted to heat energy, which is released to the surroundings.
• What is the effect on the temperature of the reaction mixture in an exothermic reaction?

  The temperature of the reaction mixture and its surroundings increases.
• What types of changes can be investigated for temperature changes in practical experiments?

  • Salts dissolving in water
  • Neutralisation reactions
  • Displacement reactions
  • Combustion reactions
• What is the formula to calculate heat energy change?

  Q = mcΔT
• What is the significance of using a lump of calcium oxide over powdered calcium oxide?

  It is less hazardous to use a lump of calcium oxide.
• What is the product formed when calcium oxide reacts with water?

  Calcium hydroxide
• What happens to the chemical energy of the products in an exothermic reaction compared to the reactants?

  The products have less chemical energy than the reactants.
• How can you tell if a reaction is exothermic when holding a test tube?

  The test tube will feel warmer due to the heat released.