Use the standard reaction enthalpies given below to determine _DrH° for the following reaction: P₄(g) + 10Cl₂(g) ? 4PCl₅(s)
_DrH°0= ?
Given:
PCl₅(s) ? PCl₃(g) + Cl₂(g) $D _ { \mathrm { r } }$ H°= +157 kJ
P₄(g) + 6Cl₂(g) ? 4PCl₃(g) $D _ { \mathrm { r } }$ H° = -1207 kJ

Question

Use the standard reaction enthalpies given below to determine _DrH° for the following reaction: P₄(g) + 10Cl₂(g) ? 4PCl₅(s)
_DrH°0= ?
Given:
PCl₅(s) ? PCl₃(g) + Cl₂(g)

D _ { \mathrm { r } }

H°= +157 kJ
P₄(g) + 6Cl₂(g) ? 4PCl₃(g)

D _ { \mathrm { r } }

H° = -1207 kJ

Quizplus · Accepted Answer

To find the reaction enthalpy for P4(g) + 10Cl2(g) → 4PCl5(s), use Hess's Law. Reverse the first reaction and multiply by 4: 4(PCl3(g) + Cl2(g) → PCl5(s)) gives -4(157 kJ) = -628 kJ. Add the second reaction: P4(g) + 6Cl2(g) → 4PCl3(g) = -1207 kJ. Total: -628 kJ + (-1207 kJ) = -1835 kJ.

Use the Standard Reaction Enthalpies Given Below to Determine DrH° DrD _ { \mathrm { r } }Dr​

Use the Standard Reaction Enthalpies Given Below to Determine _DrH° $D _ { \mathrm { r } }$