Why is magnesium + copper sulphate → magnesium sulphate + copper a displacement reaction

Magnesium displaces copper from the solution of its salt (CuSO4)

Explanation:

Magnesium + copper sulphate → magnesium sulphate + copper

Mg(s) + CuSO4(aq) → MgSO4(aq) + Cu(s)

The balanced equation above is a displacement reaction because the more reactive magnesium metal displaces copper from its solution of its salt (CuSO4) due to its higher position in the reactivity series, hence Magnesium forms its own salt solution (MgSO4) while Copper is released in free form (Cu)

the product of the pressure and volume is also constant

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.