MyQuestionIcon

4

You visited us 4 times! Enjoying our articles? Unlock Full Access!

Heat of Formation

The enthalpy ...

Question

The enthalpy formation of $H_{2} O (l)$ is $- 285.7$ kJ $m o l^{- 1}$ and enthalpy of neutralization of strong acid and base is $- 57.6$ kJ $m o l^{- 1}$ . what is the enthalpy of formation of $O H^{- 1}$ ions

Open in App

Solution

${H_{2}}_{(g)} + \frac{1}{2} {O_{2}}_{(g)} ⟶ {H_{2} O}_{(l)}; Δ H = - 285.7 k J / m o l . . . . . (1)$
Neutralisation of strong acid and base-
${H^{+}}_{(a q .)} + {O H}^{-}_{(a q .)} ⟶ {H_{2} O}_{(l)}; Δ H = - 57.6 k J / m o l$
${H_{2} O}_{(l)} ⟶ {H^{+}}_{(a q .)} + {O H}^{-}_{(a q .)}; Δ H = 57.6 k J / m o l . . . . . (2)$
Adding ${e q}^{n} (1) & (2)$ , we have
${H_{2}}_{(g)} + \frac{1}{2} {O_{2}}_{(g)} + {H_{2} O}_{(l)} ⟶ {H_{2} O}_{(l)} + {H^{+}}_{(a q .)} + {O H}^{-}_{(a q .)}; Δ H = [(- 285.7) + 57.6] k J / m o l$
${H_{2}}_{(g)} + \frac{1}{2} {O_{2}}_{(g)} ⟶ {H^{+}}_{(a q .)} + {O H}^{-}_{(a q .)}; Δ H = - 228.1 k J / m o l$
Hence the enthalpy of formation of ${O H}^{-}$ ion is $- 228.1 k J / m o l$ .

Suggest Corrections

thumbs-up

0

Similar questions

Q. The enthalpy of neutralization of a strong acid by a strong base is

- 57.32 {kJ mol}^{- 1}

. The enthalpy of formation of water and hydrogen ions are

- 285.84 {kJ mol}^{- 1}

0 {kJ mol}^{- 1}

respectively. The enthalpy of formation of the hydroxyl ion is:

Q. The enthalpy of neutralisation of a strong acid by a strong base is

- 57.32

m o l^{- 1}

. The enthalpy of formation of water is

- 285.84

m o l^{- 1}

. The enthalpy of formation of hydroxyl ion is:

Q. The enthalpy of neutralization of a weak acid in

1 M

solution with a strong base is

- 56.1 k J m o l^{- 1}

. If the enthalpy of ionization of the acid is

1.5 k J m o l^{- 1}

and enthalpy of neutralization of the strong acid with a strong base is

- 57.3 k J e q u i v^{- 1}

, what is % ionization of the weak acid in molar solution (assume the acid to be monobasic)?

Q. The standard enthalpy of formation of octane

(C_{8} H_{18})

- 250 k J / m o l

. Calculate the enthalpy of combustion of

C_{8} H_{18}

.
Given : enthalpy of formation of

C O_{2} (g)

H_{2} O (l)

- 394 k J / m o l

- 286 k J / m o l

Q. The enthalpies of formation of

O H (g)

H (g)

O (g)

k J m o l^{- 1}

k J m o l^{- 1}

k J m o l^{- 1} .

The value of bond enthalpy

O - H

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Thermochemistry

CHEMISTRY

Watch in App

explore_more_icon

Explore more

Heat of Formation

Standard XII Chemistry

Join BYJU'S Learning Program

CrossIcon