The standard enthalpy of formation of NiSO₄(s)at 25 °C is -872.9 kJ/mol.The chemical equation to which this value A)1/2 Ni(s)+ 1/2 S(s)+ 1/2 O₂(g)→ 1/2 NiSO₄(s) B)Ni(s)+ S(s)+ 4 O(g)→ NiSO₄(s) C)Ni(s)+ S(s)+ 2 O₂(g)→ NiSO₄(s) D)Ni(s)+ 1/8 S₈(s)+ 1/2 O₂(g)→ NiSO₄(s) E)NiSO₄(s)→ Ni(s)+ S(s)+ 4 O(g)

Question

Quizplus · Accepted Answer

The enthalpy of formation is defined as the enthalpy change when one mole of the compound is formed from its constituent elements in their standard states under standard conditions. The standard state of sulfur and nickel is solid, and that of oxygen is gas. Therefore, the equation must include Ni(s), S(s), and Os(g). The coefficients in the balanced equation should be such that the equation corresponds to the formation of one mole of NiSO₄(s). The correct equation is: Ni(s) + S(s) + 2 Os(g) → NiSO₄(s) The coefficient of 2 for Os(g) ensures that the equation corresponds to the formation of one mole of NiSO₄(s). The enthalpy change for this reaction is -872.9 kJ/mol, which is given in the question.

The Standard Enthalpy of Formation of NiSO4(s)at 25 °C Is

The Standard Enthalpy of Formation of NiSO₄(s)at 25 °C Is