The molar heat capacity of water at constant pressure, CP is 75 J K -1 mol -1. When 10 kJ of heat is supplied to 1 kg water which is free to expand, the increase in temperature of water is

Question

The molar heat capacity of water at constant pressure, CP is 75 J K -1 mol -1. When 10 kJ of heat is supplied to 1 kg water which is free to expand, the increase in temperature of water is (A) 2.4 K (B) 4.8 K (C) 3.3 K (D) 7.2 K

Tardigrade Admin · Accepted Answer

q m = mc Δ T qm=10 kJ or 10000 J , m =1000 g c=75 J K -1 mol -1 . Number of moles =(1000/18)=55.5 mol Δ T =(10000/55.5× 75)=2.4 K

Q. The molar heat capacity of water at constant pressure, $C_{P}$ is $75 J K^{- 1} m o l^{- 1}$ . When $10 k J$ of heat is supplied to $1 k g$ water which is free to expand, the increase in temperature of water is

2.4 K

4.8 K

3.3 K

7.2 K

$q_{m} = m c Δ T$
$q_{m} = 10 k J$ or $10000 J, m = 1000 g$
$c = 75 J K^{- 1} m o l^{- 1} .$
Number of moles $= \frac{1000}{18} = 55.5 m o l$
$Δ T = \frac{10000}{55.5 \times 75} = 2.4 K$

Q. The molar heat capacity of water at constant pressure, CP​ is 75JK−1mol−1. When 10kJ of heat is supplied to 1kg water which is free to expand, the increase in temperature of water is