Question

The molar heat capacity ( $C_p$) of water at constant pressure is 75 $J{K}^{-1}mol{e}^{-1}$. The increase in temperature (in K) of 100 g of water when 2kJ of heat is supplied to it is:

• A. 2.4 K
• B. 3.6 K
• C. 4.8 K
• D. 5.2 K

Answer 1

The correct option is C 4.8 K

Given: molar heat capacity ( $C_p$) : 75 $J{K}^{-1}mol{e}^{-1}$ = $\frac{75}{18}$ $J{K}^{-1}{g}^{-1}$
mass of water = 100 g
We know, $q=m{C}_p\Delta T$
where m = mass of the water
q = 2000 J
So, 2000 J = $100\times \frac{75}{18}\Delta T$
On calculating, $\Delta$T = increase in temperature = 4.8 K