q is the amount of heat transferred to a system whereas is used to describe the change in enthalpy. Enthalpy is the total potential energy of a system, which is associated with the heat transferred to/from a system (q).

Is enthalpy change Q or delta H?

Enthalpy as a Composite Function Comparing the previous two equations shows that at constant pressure, the change in the enthalpy of a system is equal to the heat flow: ΔH=qp.

How do you calculate enthalpy change from Q?

The formula q = mc∆T can be used to calculate the enthalpy change per mole of a substance which dissolves in water to form a solution. When an acid reacts with an alkali, a neutralisation reaction occurs. The enthalpy change of the neutralisation reaction can be calculated per mole of water formed in the reaction.