For water $Δ_{v a p} H = 41 k J m o l^{- 1}$ at 373K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is_________kJ mol^-1. [Use: R = 8.3 J mol^-1 K^-1]

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alok kumar singh | Contributor-Level 10

3 months ago

$Δ H_{v a p} = 41 K J m o l^{- 1}$

$Δ H = Δ E + Δ n R T$

$H_{2} O_{(l)} \to H_{2} O_{v a p}$

$Δ n = 1$

R = 8.3 JK^-1 mol^-1

T = 373 K

$Δ$ E (Change of internal energy) = $Δ H - Δ n R T$

$? Δ E = 41 - \frac{1 \times 8.3 \times 373}{1000} k J m o l^{- 1} = 41 - 3.09 k J m o l^{- 1} = 37.91 k J m o l^{- 1}$

Nearest integer = 38.

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For water $Δ_{v a p} H = 41 k J m o l^{- 1}$ at 373K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is_________kJ mol^-1. [Use: R = 8.3 J mol^-1 K^-1]

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For water Δ v a p H = 4 1 k J m o l − 1 at 373K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is_________kJ mol-1. [Use: R = 8.3 J mol-1 K-1]

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For water $Δ_{v a p} H = 41 k J m o l^{- 1}$ at 373K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is_________kJ mol^-1. [Use: R = 8.3 J mol^-1 K^-1]