Question

Use the given standard enthalpies of formation to calculate δH° in the unit of kJ for the following reaction: 3Fe₂O₃(s)+CO(g)→2Fe₃O₄(s)+CO₂(g).

a. -100 kJ
b. -200 kJ
c. +100 kJ
d. +200 kJ

Answer 1

To calculate the standard enthalpy change (ΔH°) for the given reaction, we can use the standard enthalpies of formation and apply Hess's Law of Heat Summation. The ΔH° for the reaction is -166.4 kJ.

Step-by-step explanation:

To calculate the standard enthalpy change (ΔH°) for the reaction,

• 3Fe₂O₃(s) + CO(g) → 2Fe₃O₄(s) + CO₂(g)

we need to use the given standard enthalpies of formation and apply the Hess's Law of Heat Summation.

The standard enthalpies of formation for the substances involved in the reaction are:

• Fe₂O₃(s): -824.2 kJ/mol
• CO(g): -110.5 kJ/mol
• Fe₃O₄(s): -1117.8 kJ/mol
• CO₂(g): -393.5 kJ/mol

Using these values, we can calculate the ΔH° for the reaction:

• (3 x ΔH° of Fe₂O₃(s)) + (1 x ΔH° of CO(g)) - (2 x ΔH° of Fe₃O₄(s)) - (1 x ΔH° of CO₂(g))
• (3 x -824.2) + (1 x -110.5) - (2 x -1117.8) - (1 x -393.5)
• -2472.6 - 110.5 + 2235.6 + 393.5
• -166.4 kJ

Therefore, the ΔH° for the reaction is -166.4 kJ.