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Paragraph: Enthalpy change for a chemical reaction can be calculated from bond enthalpy data. Bond enthalpy depends upon structural environment of the bond. From the data given below, answer the questions that follow. H _t [ PCl ₃( ~g ) ]=-320 ~kJ ~mol ⁻¹ ; H _ t [ P ( g )]=315 ~kJ ~mol ⁻¹ and H _t [ PCl ₅( ~g ) ]=-400 ~kJ ~mol ⁻¹ Question: Calculate enthalpy of formation of C ( . diamond) if enthalpy of atomisation

Options

  1. A2.9 ~kJ ~mol ⁻¹
  2. B1.9 ~kJ ~mol ⁻¹
  3. C3.3 ~kJ ~mol ⁻¹
  4. D0.9 ~kJ ~mol ⁻¹

Correct answer

B. 1.9 ~kJ ~mol ⁻¹

Step-by-step solution

aligned & C(graphite) C(diamond) & H_f( diamond )=710-2 354.05=1.9 ~kJ ~mol ⁻¹ aligned

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