The reaction that represents the standard enthalpy of formation for sucrose (C₁₂H₂₂O₁₁) is: A) C₁₂H₂₂O₁₁(s) + 12 O₂ $\rarr$ 12 CO₂(g) + 11 H₂O(g) B) 12 C(diamond) + 11 H₂(g) + 11/2 O₂(g) $\rarr$ C₁₂H₂₂O₁₁(s) C) 12 C(graphite) + 11 H₂(g) + 11/2 O₂(g) $\rarr$ C₁₂H₂₂O₁₁(s) D) 24 C(diamond) + 22 H₂(g) + 11 O₂(g) $\rarr$ 2 C₁₂H₂₂O₁₁(s) E) C₁₂H₂₂O₁₁(s) $\rarr$ 2 C(graphite) + 11 H₂(g) + 11/2 O₂(g)

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Quizplus · Accepted Answer

The standard enthalpy of formation is the enthalpy change for the formation of one mole of a compound from its constituent elements in their standard states. The balanced equation for the formation of sucrose from its constituent elements is: 12 C(graphite) + 11 H2S(g) + 11/2 O2(g) → C₁₂H₂₂O₁₁(s) Therefore, option C is the correct choice as it shows the formation of sucrose from its constituent elements in their standard states. Option A shows the combustion of sucrose and option B shows the reverse reaction of the combustion of sucrose. Option D shows the formation of two moles of sucrose from its constituent elements, which is not the standard enthalpy of formation, and option E shows the formation of sucrose from graphite, hydrogen sulfide, and oxygen, which is not the standard state of the elements.

The Reaction That Represents the Standard Enthalpy of Formation for Sucrose