The standard heat of formation of carbon disulphide (l) given that the standard

The standard heat of formation of carbon disulphide (l) given that the standard heat of combustion of carbon(s) , sulphur(s) and carbon disulphide(l) are -393.3, -293.72 and -1108.76 kJ mol⁻¹ respectively is

Options

(a) 128.02 kJ mol⁻¹
(b) 12.802 kJ mol⁻¹
(c) -128.02 kJ mol⁻¹
(d) -12.802 kJ mol⁻¹

Correct Answer:

128.02 kJ mol⁻¹

Explanation:

(i) C(s) + O₂(g) → CO₂(g); ΔH₁ = -393.3 kJ.
(ii) S(s) + O₂(g) → SO₂(g); ΔH₂ = -293.72 kJ.
(iii) CS₂(l) + 3O₂(g) → CO₂ + 2SO₂ ; ΔH₃ = -1108.76 kJ.
On adding (i) and (ii) and subtracting (iii), we get,
C(s) + 2S(s) → CS₂(g), ΔH = -393.3 + 2 (-293.72) + 1108.76 = +128.02 kJ mol⁻¹.

admin:

Related Questions

  1. During change of O₂ to O₂⁻ ion, the electron adds on which one of the following
  2. If the value of Cp for nitrogen gas is 7 JK⁻¹mol⁻¹ , then the value
  3. Treatment of a mixture of CH₃Cl and C₂H₅Cl with sodium in dry ether can generat
  4. The oxidation number of P in Mg₂P₂O₇ is
  5. Which of the following is non-permissible?