Q.
The molar heat capacity of water at constant pressure is 84JK−1mol−1. When 1.0kJ of heat is supplied to 100g of water which is free to expand; the increase in temperature of water is
Molar heat capacity of water per gram =84/18=4.7J
As we know that; q=1kJ=1000J
molar heat capacity (q)=m×c×ΔT
where m= mass, c= specific heat capacity ΔT= temperature change ∴q=100×4.7×ΔT
or 1000=100×4.7×ΔT ΔT=100×4.71000=2.1K
Thus, the increase in temperature of water is 2.1K.