In the formula H = -ml, what does 'm' represent?

In the formula H = -ml, the correct interpretation of 'm' is the mass of the substance involved in the heat transfer process. This equation is typically derived from the principles of thermodynamics, specifically from the latent heat concepts, where 'H' represents the heat absorbed or released during a phase change, 'l' represents the latent heat (the heat per unit mass necessary for the phase change), and 'm' signifies the mass of the substance that is undergoing this change.

The negative sign indicates that heat is absorbed when the process is endothermic (such as melting), or released when it is exothermic (like freezing). Thus, the mass plays a crucial role in determining how much heat will be involved in such changes. For instance, doubling the mass of the substance would result in double the amount of heat absorbed or released, provided the latent heat remains constant.

This relationship shows that heat transfer is directly proportional to the mass of the substance, underscoring the correct identification of 'm' as the mass in this context.