How much energy is released when 42.5 g of water freezes?
Concepts and reason
Enthalpy of freezing () is used to calculate energy needed to release when liquid becomes solid (freeze).
Heat energy equation:
Heat is q.
Number of moles involved is n.
Enthalpy of freezing is .
In this question, given mass of water is 42.5 g which is converted into moles of water to calculate heat by using molar mass of water, 18.0 g/mol.
Heat energy released when water freezing is calculated by substituting the values of moles of water and enthalpy of freezing into the heat energy equation as in kJ.