Calculate the standard enthalpy of formation of CH 3 OH l from the following data-CH 3 OH l-3-2 O 2g- CO 2g-2 H 2 O l - -r H-726 kJ mol -1C g- O 2g- CO 2g - -c H-393 kJ mol -1H 2g-1-2 O 2g- H 2 O l - -H H-286 kJ mol -1

The reaction that takes place during the formation of CH3OH(l) can be written as: C(s) + 2H2O(g) + O2(g) CH3OH(l) (1) The reaction (1) can be obtained fro ...

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Standard XII

Chemistry

Polyhalogen Compounds

Calculate the...

Question

Calculate the standard enthalpy of formation of CH₃OH₍_l₎ from the following data:

CH₃OH₍_l₎ + O₂₍_g₎ CO₂₍_g₎ + 2H₂O₍_l₎ ; Δ_rH^θ = –726 kJ mol^–1

C₍_g₎ + O₂₍_g₎ CO₂₍_g₎ ; Δ_cH^θ = –393 kJ mol^–1

H₂₍_g₎ +O₂₍_g₎ H₂O₍_l₎ ; Δ_fH^θ = –286 kJ mol^–1.

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Solution

The reaction that takes place during the formation of CH₃OH₍_l₎ can be written as:

C₍_s₎ + 2H₂O₍_g₎ + O₂₍_g₎ CH₃OH₍_l₎ (1)

The reaction (1) can be obtained from the given reactions by following the algebraic calculations as:

Equation (ii) + 2 × equation (iii) – equation (i)

Δ_fH^θ [CH₃OH₍_l₎] = Δ_cH^θ+ 2Δ_fH^θ [H₂O₍_l₎] – Δ_rH^θ

= (–393 kJ mol^–1) + 2(–286 kJ mol^–1) – (–726 kJ mol^–1)

= (–393 – 572 + 726) kJ mol^–1

Δ_fH^θ [CH₃OH₍_l₎] = –239 kJ mol^–1

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C H_{3} O H (1) + \frac{3}{2} O_{2} (g) \to C O_{2} (g) + 2 H_{2} O (I); Δ, H^{⊖} = - 726 k J m o l^{- 1}

C (g r a p h i t e) + O_{2} (g) \to C O_{2} (g); Δ_{c} H^{⊖} = - 393 k J m o l^{- 1}

H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (I); Δ_{f} H^{⊖} = - 286 k J m o l^{- 1}

Calculate the standard enthalpy of formation of

{C H}_{3} O H (l)

from the following data:

Q. Calculate the standard enthalpy of formation of

C H_{3} O H (I)

from the following data :

C H_{3} O H (I) + \frac{3}{2} O_{2} (g) \to C O_{2} (g) + 2 H_{2} O (l); △_{r} H^{θ} = - 726 k J m p l^{- 1}

C_{(g r a p h i t e)} + O_{2} (g) \to C O_{2} (g); △_{c} H^{θ} = - 393 k J m o l^{- 1}

H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (l); △_{f} H^{θ} = - 286 k J m o l^{- 1}

Q. Calculate the standard enthalpy of formation of

C H_{3} O H (l)

from the following data.

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}

C(graphite)

+ 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}

From the following data of heats of combustion, find the heat of formation of

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); △_{r} H^{⊖} = - 726 k J

C (s) + O_{2} (g) \to C O_{2} (g), Δ H = - 394 k J

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

Q. From the following data of heats of combustion, find the heat of formation of

{C H}_{3} O H (l)

{C H}_{3} O H (l) + \frac{3}{2} O_{2} (g) ⟶ C O_{2} (g) + 2 H_{2} O (l); Δ H = - 726 k J

C (s) + O_{2} (g) ⟶ C O_{2} (g); Δ H = - 394 k J

H_{2} (g) + \frac{1}{2} O_{2} (g) ⟶ H_{2} O (l); Δ H = - 286 k J

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Calculate the standard enthalpy of formation of CH3OH(l) from the following data: CH3OH(l) + O2(g) CO2(g) + 2H2O(l) ; ΔrHθ = –726 kJ mol–1 C(g) + O2(g) CO2(g) ; ΔcHθ = –393 kJ mol–1 H2(g) +O2(g) H2O(l) ; ΔfHθ = –286 kJ mol–1.