Heat of Fusion Calculator:
Enter the values of amount of heat energy absorbed or released, q(J) and mass, m(g) to determine the value of Heat of Fusion, HHf(J/g).
Heat of Fusion Formula:
The heat of fusion (also known as enthalpy of fusion) is the amount of heat energy required to convert a unit mass of a solid into a liquid at its melting point without changing its temperature. This energy is needed to break the intermolecular forces holding the particles together in the solid phase, allowing them to transition into the more loosely held liquid phase.
The value of heat of fusion varies for different substances based on their molecular structure and bonding. For example, substances with strong intermolecular forces, like water, require a high heat of fusion to change from solid to liquid. In practical applications, understanding the heat of fusion is important in industries such as metallurgy, food processing, and climate science, where phase changes are common.
In a calculation, the heat of fusion (HHf) can be found by dividing the heat absorbed or released (q) by the mass of the substance (m) undergoing the phase change. This formula is applicable for situations where the entire substance is melting or freezing, with no change in temperature during the phase change.
Heat of Fusion, HHf(J/g) in Joules per gram equals the amount of heat energy absorbed or released, q(J) in Joules divided by the mass, m(g) in grams of the substance.
Heat of Fusion, HHf(J/g) = q(J) / m(g)
HHf(J/g) = heat of fusion in Joules per gram, J/g.
q(J) = amount of heat energy absorbed or released in Joules, J.
m(g) = mass in grams, g.
Heat of Fusion Calculation:
1.A 200-gram sample of ice absorbs 67000 J of heat energy as it melts at 0°C. Determine the heat of fusion of ice.
Given: q(J) = 67000J, m(g) = 200g.
Heat of Fusion, HHf(J/g) = q(J) / m(g)
HHf(J/g) = 67000 / 200
HHf(J/g) = 335J/g.
2.If the heat of fusion of a substance is 250J/g and 50 grams of this substance melts, how much heat energy (q) is absorbed?
Given: HHf(J/g) = 250J/g, m(g) = 50g.
Heat of Fusion, HHf(J/g) = q(J) / m(g)
q(J) = HHf(J/g) * m(g)
q(J) = 250 * 50
q(J) = 12500J.