Question

Ice melts into water. The correct equation to calculate the heat of this reaction is...

O q=MCAT
O q=mAHV
O q=mAHE
O q=mc^2

Answer 1

The correct equation to calculate the heat when ice melts into water is q = m∆Hf, involving the mass of ice and the enthalpy of fusion, which represents the heat needed to melt ice at 0.0°C into liquid water.

Step-by-step explanation:

The correct equation to calculate the heat (q) of the reaction when ice melts into water is q = m∆Hf, where m is the mass of the ice, and ∆Hf is the enthalpy of fusion, the amount of heat needed to convert ice at its melting point to liquid water without changing its temperature.

This phenomenon is also known as the heat of fusion. While the general equation q = mC∆T is used for calculating heat transfer associated with temperature changes, in the case of melting ice the temperature remains constant at 0.0°C and thus, C∆T (specific heat times temperature change) is not involved. Instead, the enthalpy of fusion is used to represent the heat required to change the state from solid to liquid at constant temperature.

Answer 2

q=mAHf

Step-by-step explanation:

When water change form from solid(ice) to liquid, it will need heat that depends on the heat of fusion(Hfus). If the form changed from liquid to gas it will use the heat of vaporization(Hvap) instead. The heat of fusion usually written just AT

q=MCAT is used to calculate heat when temperature change(AT = delta T= difference in temperature)

q=mAHvap is wrong because you need if the form change from liquid to gas

q=mc^2 is wrong because it describes the relation of mass and energy, not the form.

The answer should be q=mAHf