Explore Westonci.ca, the premier Q&A site that helps you find precise answers to your questions, no matter the topic. Our platform connects you with professionals ready to provide precise answers to all your questions in various areas of expertise. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

Determine [tex]\Delta H^{\circ}[/tex] for the following thermochemical equation:

[tex]\[
\begin{array}{l}
Fe_2O_3(s) + 3CO(g) \rightarrow 2Fe(s) + 3CO_2(g); \Delta H^{\circ} = -26.8 \, \text{kJ} \\
FeO(s) + CO(g) \rightarrow Fe(s) + CO_2(g); \Delta H^{\circ} = -16.5 \, \text{kJ}
\end{array}
\][/tex]

[tex]\[
Fe_2O_3(s) + CO(g) \rightarrow 2FeO(s) + CO_2(g)
\][/tex]


Sagot :

Sure, let's determine the ΔH° for the reaction [tex]\( \text{Fe}_2\text{O}_3(\text{s}) + \text{CO}(\text{g}) \rightarrow 2 \text{FeO}(\text{s}) + \text{CO}_2(\text{g}) \)[/tex] using Hess's Law. We will combine the given reactions in a way that will lead to the desired reaction.

The given reactions and their enthalpy changes are:

1. [tex]\( \text{Fe}_2\text{O}_3(\text{s}) + 3 \text{CO}(\text{g}) \rightarrow 2 \text{Fe}(\text{s}) + 3 \text{CO}_2(\text{g}) \)[/tex]; [tex]\( \Delta H_1^{\circ} = -26.8 \ \text{kJ} \)[/tex]
2. [tex]\( \text{FeO}(\text{s}) + \text{CO}(\text{g}) \rightarrow \text{Fe}(\text{s}) + \text{CO}_2(\text{g}) \)[/tex]; [tex]\( \Delta H_2^{\circ} = -16.5 \ \text{kJ} \)[/tex]

We need to manipulate these reactions to get the target reaction:

[tex]\[ \text{Fe}_2\text{O}_3(\text{s}) + \text{CO}(\text{g}) \rightarrow 2 \text{FeO}(\text{s}) + \text{CO}_2(\text{g}) \][/tex]

### Step 1: Reverse the Second Reaction
First, reverse the second reaction to produce:
[tex]\[ \text{Fe}(\text{s}) + \text{CO}_2(\text{g}) \rightarrow \text{FeO}(\text{s}) + \text{CO}(\text{g}) \][/tex]
Reversing the reaction changes the sign of ΔH:
[tex]\[ \Delta H_{\text{rev2}}^{\circ} = +16.5 \ \text{kJ} \][/tex]

### Step 2: Scale the Reversed Second Reaction
Next, we need to match the stoichiometry. Multiply the reversed reaction by 2:
[tex]\[ 2 \text{Fe}(\text{s}) + 2 \text{CO}_2(\text{g}) \rightarrow 2 \text{FeO}(\text{s}) + 2 \text{CO}(\text{g}) \][/tex]
This doubles the enthalpy change:
[tex]\[ \Delta H_{\text{rev2 and scaled}}^{\circ} = 2 \times 16.5 \ \text{kJ} = 33.0 \ \text{kJ} \][/tex]

### Step 3: Add the Adjusted Reactions
Finally, add the first reaction and the scaled reversed reaction:
1. [tex]\( \text{Fe}_2\text{O}_3(\text{s}) + 3 \text{CO}(\text{g}) \rightarrow 2 \text{Fe}(\text{s}) + 3 \text{CO}_2(\text{g}) \)[/tex]; [tex]\( \Delta H_1^{\circ} = -26.8 \ \text{kJ} \)[/tex]
2. [tex]\( 2 \text{Fe}(\text{s}) + 2 \text{CO}_2(\text{g}) \rightarrow 2 \text{FeO}(\text{s}) + 2 \text{CO}(\text{g}) \)[/tex]; [tex]\( \Delta H_{\text{rev2 and scaled}}^{\circ} = 33.0 \ \text{kJ} \)[/tex]

Adding these reactions:
[tex]\[ \text{Fe}_2\text{O}_3(\text{s}) + 3 \text{CO}(\text{g}) + 2 \text{Fe}(\text{s}) + 2 \text{CO}_2(\text{g}) \rightarrow 2 \text{Fe}(\text{s}) + 3 \text{CO}_2(\text{g}) + 2 \text{FeO}(\text{s}) + 2 \text{CO}(\text{g}) \][/tex]

### Simplifying
Cancel out the common terms on both sides:
[tex]\[ \text{Fe}_2\text{O}_3(\text{s}) + \text{CO}(\text{g}) \rightarrow 2 \text{FeO}(\text{s}) + \text{CO}_2(\text{g}) \][/tex]

### Calculate ΔH for the Target Reaction
[tex]\[ \Delta H_{\text{target}}^{\circ} = -26.8 \ \text{kJ} + 33.0 \ \text{kJ} = 6.2 \ \text{kJ} \][/tex]

So, the enthalpy change for the reaction [tex]\( \text{Fe}_2\text{O}_3(\text{s}) + \text{CO}(\text{g}) \rightarrow 2 \text{FeO}(\text{s}) + \text{CO}_2(\text{g}) \)[/tex] is [tex]\( 6.2 \ \text{kJ} \)[/tex].
Your visit means a lot to us. Don't hesitate to return for more reliable answers to any questions you may have. We appreciate your time. Please revisit us for more reliable answers to any questions you may have. Stay curious and keep coming back to Westonci.ca for answers to all your burning questions.