Use the information provided to determine Δ_rH° for the following reaction: Δ_fH°(kJ mol^-1) CH₄(g) + 4 Cl₂(g) → CCl₄(g) + 4 HCl(g) Δ_rH°= ?
CH₄(g) -75
CCl₄(g) -96
HCl(g) -92

Question

Use the information provided to determine Δ_rH° for the following reaction: Δ_fH°(kJ mol^-1)CH₄(g)+ 4 Cl₂(g)→ CCl₄(g)+ 4 HCl(g)Δ_rH°= ? CH₄(g) -75 CCl₄(g) -96 HCl(g) -92

Quizplus · Accepted Answer

Δ_fH° for the reaction can be calculated by considering the standard enthalpies of formation of the reactants and products: Δ_fH°(CCl4) + 4Δ_fH°(HCl) - Δ_fH°(CHCl3) - 4Δ_fH°(Cl2) Δ_fH°(CCl4) = -95.7 kJ/mol Δ_fH°(HCl) = -92.31 kJ/mol Δ_fH°(CHCl3) = -104.7 kJ/mol Δ_fH°(Cl2) = 0 kJ/mol (diatomic elements have zero standard enthalpies of formation) Δ_rH° = ΣΔ_fH°(products) - ΣΔ_fH°(reactants) Δ_rH° = (-92.31 kJ/mol x 4) + (-96.7 kJ/mol) - (-75 kJ/mol) = -389 kJ/mol Therefore, the best choice is A, which corresponds to Δ_rH° = -389 kJ/mol.

Use the Information Provided to Determine ΔrH° for the Following

Use the Information Provided to Determine Δ_rH° for the Following