Given that 1 g of water in liquid phase has volume 1 cm3 and in vapour phase 1671 cm3 at atmospheric pressure and the latent heat of vaporization of water is 2256 J/g; the change in the internal energy in joules for 1 g of water at 373 K when it changes from liquid phase to vapour phase at the same temperature is:

Question

Given that 1 g of water in liquid phase has volume 1 cm3 and in vapour phase 1671 cm3 at atmospheric pressure and the latent heat of vaporization of water is 2256 J/g; the change in the internal energy in joules for 1 g of water at 373 K when it changes from liquid phase to vapour phase at the same temperature is: (A) 2256 (B) 167 (C) 2089 (D) 1

Tardigrade Admin · Accepted Answer

Δ Q =Δ U +Δ W ⇒ 2256=Δ U + P 0 Δ V =Δ U +105(1670 × 10-6) ⇒ Δ U =2089 J

$2256$

$167$

$2089$

$1$

$Δ Q = Δ U + Δ W \Rightarrow 2256 = Δ U + P_{0} Δ V = Δ U + 1 0^{5} (1670 \times 1 0^{- 6})$
$\Rightarrow Δ U = 2089 J$

2256

167

2089

1

ΔQ=ΔU+ΔW⇒2256=ΔU+P0​ΔV=ΔU+105(1670×10−6) ⇒ΔU=2089J

$2256$

$167$

$2089$

$1$

$Δ Q = Δ U + Δ W \Rightarrow 2256 = Δ U + P_{0} Δ V = Δ U + 1 0^{5} (1670 \times 1 0^{- 6})$
$\Rightarrow Δ U = 2089 J$