You visited us 1 times! Enjoying our articles? Unlock Full Access!

Enthalpy

H 2 g+ 1 2 O ...

Question

$H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (l); {Δ H}_{295 K} = - 285.8 k J .$
The molar enthalpy of vapourisation of water at 1 atm and $25^{o} C$ is 44 kJ. The standard enthalpy of formation of 1 mole of water vapour at $25^{o} C$ is:

241.8 kJ

No worries! We‘ve got your back. Try BYJU‘S free classes today!

-241.8 kJ

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

-329.8 kJ

No worries! We‘ve got your back. Try BYJU‘S free classes today!

329.8 kJ

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B -241.8 kJ
$H_{2} (g) + \frac{1}{2} O_{2} (g) ⟶ H_{2} O (l);$ $Δ H_{1} = - 285.8 k J$

$H_{2} O (l) ⟶ H_{2} O (g);$ $Δ H_{2} = 44 k J$

Formation of water vapour:

$H_{2} (g) + \frac{1}{2} O_{2} (g) ⟶ H_{2} O (g);$ $Δ H_{3}$

Here, $Δ H_{3} = Δ H_{1} + Δ H_{2}$

$Δ H_{3} = - 285.8 + 44$

$Δ H_{3} = - 241.8 k J$

Suggest Corrections

Similar questions

H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (l); Δ H

298 K = - 285.8 k J

25^{o} C

44 k J

Δ_{f} H^{o}

C O_{2} (g), C O (g)

H_{2} O (l)

k J m o l^{- 1}

k J m o l^{- 1}

C O_{2} (g) + H_{2} (g) \to C O (g) + H_{2} O (l)

H_{(a q)}^{+} + O H_{(a q)}^{-} = H_{2} O_{(l)}, Δ H = - X_{1}

m o l^{- 1}

H_{2 (g)} + \frac{1}{2} O_{2 (g)} = H_{2} O_{(l)}, Δ H = X_{2}

m o l^{- 1}

C O_{2 (g)} + H_{2 (g)} = C O_{(g)} + H_{2} O_{(l)} - X_{3}

m o l^{- 1}

C_{2} H_{2 (g)} + \frac{5}{2} O_{2 (g)} = 2 C O_{2 (g)} + H_{2} O_{(l)} + X_{4}

m o l^{- 1}

H_{2} O_{(l)}

C H_{3} O H (l)

C H_{3} O H (l) + \frac{3}{2} O_{2} (g) \to C O_{2} (g) + 2 H_{2} O (l)

Δ H^{o} = - 726

m o l^{- 1}

+ O_{2} (g) \to C O_{2} (g);

Δ_{c} H^{0} = - 393

m o l^{- 1}

H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (l);

Δ_{t} H^{o} = - 286

m o l^{- 1}

H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (l), △ H = - 286 kJ

H_{2} (g) + \frac{1}{2} O_{2} (g), \to H_{2} O (g), △ H = - 245.5 kJ

Join BYJU'S Learning Program