Question

Part A Calculate the standard enthalpy change for the reaction 2A+B⇌2C+2D Use the following data: Substance ΔH∘f (kJ/mol) A -263 B -409 C 199 D -485 Express your answer to three significant figures and include the appropriate units.

Answer 1

A)

we have:

Hof(A) = -263.0 KJ/mol

Hof(B) = -409.0 KJ/mol

Hof(C) = 199.0 KJ/mol

Hof(D) = -485.0 KJ/mol

we have the Balanced chemical equation as:

2 A + B ---> 2 C + D

deltaHo rxn = 2*Hof(C) + 1*Hof(D) - 2*Hof( A) - 1*Hof(B)

deltaHo rxn = 2*(199.0) + 1*(-485.0) - 2*(-263.0) - 1*(-409.0)

deltaHo rxn = 848 KJ/mol

Answer: 848 KJ/mol