The mass of ice can affect the determination of the enthalpy of fusion because the amount of heat needed to change the phase of a substance depends on its mass. The equation for determining the enthalpy of fusion is:ΔH = m x ΔHfWhere ΔH is the change in enthalpy, m is the mass of the substance, and ΔHf is the enthalpy of fusion. If the mass of ice is different, then the amount of heat needed to change its phase will also be different. A larger mass of ice will require more heat to change its phase, while a smaller mass of ice will require less heat. Therefore, the mass of ice can affect the determination of the enthalpy of fusion by changing the amount of heat needed to change its phase. It is important to keep the mass of ice constant when determining the enthalpy of fusion in order to get accurate results. If the mass of ice is not constant, then the results may not be accurate because the amount of heat needed to change the phase of the substance will also be different.