Constants Heat of fusion ( H fus) is used for calculations involving a phase cha
ID: 587208 • Letter: C
Question
Constants
Heat of fusion (Hfus) is used for calculations involving a phase change between solid and liquid, with no temperature change. For H2O, Hfus=6.02 kJ/mol.
Specific heat capacity (C) is used for calculations that involve a temperature change, but no phase change. For liquid water, C=4.184 J/(gC).
Heat of vaporization (Hvap) is used for calculations involving a phase change between liquid and gas, with no temperature change. For H2O, Hvap=40.7 kJ/mol.
1. How much heat is required to melt 63.0 g of ice at its melting point?
Explanation / Answer
when ice is at its melting point, (0 deg.c), one need to supply heat of fusion to melt it
Heat of fusion = 6.02 Kj/mole, molar mass of ice = 18 g/mole,
mole of ice = mass of ice/molar mass of water= 63/18 =3.5
heat required to melt= heat of fusion in Kj/mole* moles of water(ice)= 6.02KJ/mole*3.5 moles =21.1 KJ