Required practical: measure an enthalpy change.

In the subtopic Calorimetry and enthalpy measurements, this AQA A-Level Chemistry 7405 learning objective focuses on required practical: measure an enthalpy change. It belongs to Energetics, so revision should stay anchored to this exact subtopic rather than drifting into a generic GCSE-level chemistry summary. Approved keywords to use include required practical. Enthalpy change. means the heat change associated with a chemical reaction at constant pressure Avoid the mistake of students often forget to convert the mass to kilograms when using the formula q = mcΔT, leading to incorrect calculations of heat energy transferred; instead, to fix this, remember to convert the mass from grams to kilograms before substituting it into the formula. For example, if you have 200 g of water, convert it to kg: 200 g = 0.2 kg. Then use the formula: q = mcΔT, where m = 0.2 kg, c = 4.18 J/g°C (or 4180 J/kg°C), and ΔT is the temperature change For exam answers, when conducting calorimetry experiments, ensure to accurately measure the mass of the solution and the temperature change to calculate the enthalpy change effectively