IDNLearn.com provides a comprehensive platform for finding accurate answers. Discover comprehensive answers to your questions from our community of experienced professionals.

Using the table of standard formation enthalpies found under the ALEKS Data tab, calculate the reaction enthalpy of this reaction under standard conditions:

[tex]\[ 2 \text{CH}_3\text{OH} (l) + 3 \text{O}_2 (g) \rightarrow 2 \text{CO}_2 (g) + 4 \text{H}_2\text{O} (l) \][/tex]

Round your answer to the nearest kJ.

[tex]\(\square\)[/tex] kJ


Sagot :

To calculate the reaction enthalpy ([tex]\(\Delta H\)[/tex]) for the reaction:

[tex]\[2 \text{CH}_3\text{OH (l)} + 3 \text{O}_2\text{(g)} \rightarrow 2 \text{CO}_2\text{(g)} + 4 \text{H}_2\text{O (l)}\][/tex]

we will utilize the standard enthalpies of formation for the compounds involved. The standard enthalpy of formation ([tex]\(\Delta H_f^\circ\)[/tex]) is the heat change associated with the formation of one mole of a compound from its elements in their standard states.

The standard enthalpies of formation ([tex]\(\Delta H_f^\circ\)[/tex]) values given are:
- [tex]\(\Delta H_f^\circ\)[/tex] for CH[tex]\(_3\)[/tex]OH (l) = -238.7 kJ/mol
- [tex]\(\Delta H_f^\circ\)[/tex] for O[tex]\(_2\)[/tex] (g) = 0 kJ/mol (since it is in its standard state)
- [tex]\(\Delta H_f^\circ\)[/tex] for CO[tex]\(_2\)[/tex] (g) = -393.5 kJ/mol
- [tex]\(\Delta H_f^\circ\)[/tex] for H[tex]\(_2\)[/tex]O (l) = -285.8 kJ/mol

First, we need to calculate the total enthalpy of the products and the reactants separately.

### Step 1: Calculate the total enthalpy of the products

The products are 2 moles of CO[tex]\(_2\)[/tex] (g) and 4 moles of H[tex]\(_2\)[/tex]O (l). Their enthalpies are calculated as follows:

[tex]\[ \text{Enthalpy of } \text{CO}_2 = 2 \text{ moles} \times (-393.5 \text{ kJ/mol}) = -787.0 \text{ kJ} \][/tex]

[tex]\[ \text{Enthalpy of } \text{H}_2\text{O} = 4 \text{ moles} \times (-285.8 \text{ kJ/mol}) = -1143.2 \text{ kJ} \][/tex]

Total enthalpy of the products:

[tex]\[ \text{Enthalpy}_{\text{products}} = -787.0 \text{ kJ} + -1143.2 \text{ kJ} = -1930.2 \text{ kJ} \][/tex]

### Step 2: Calculate the total enthalpy of the reactants

The reactants are 2 moles of CH[tex]\(_3\)[/tex]OH (l) and 3 moles of O[tex]\(_2\)[/tex] (g). Their enthalpies are calculated as follows (since the enthalpy of formation of O[tex]\(_2\)[/tex] in its standard state is zero):

[tex]\[ \text{Enthalpy of } \text{CH}_3\text{OH} = 2 \text{ moles} \times (-238.7 \text{ kJ/mol}) = -477.4 \text{ kJ} \][/tex]

[tex]\[ \text{Enthalpy of } \text{O}_2 = 3 \text{ moles} \times 0 \text{ kJ/mol} = 0 \text{ kJ} \][/tex]

Total enthalpy of the reactants:

[tex]\[ \text{Enthalpy}_{\text{reactants}} = -477.4 \text{ kJ} + 0 \text{ kJ} = -477.4 \text{ kJ} \][/tex]

### Step 3: Calculate the reaction enthalpy ([tex]\(\Delta H\)[/tex])

The reaction enthalpy is the difference between the total enthalpy of the products and the total enthalpy of the reactants:

[tex]\[ \Delta H = \text{Enthalpy}_{\text{products}} - \text{Enthalpy}_{\text{reactants}} \][/tex]

[tex]\[ \Delta H = -1930.2 \text{ kJ} - (-477.4 \text{ kJ}) = -1930.2 \text{ kJ} + 477.4 \text{ kJ} = -1452.8 \text{ kJ} \][/tex]

### Step 4: Round to the nearest kJ

The final reaction enthalpy, rounded to the nearest kJ, is:

[tex]\[ \Delta H \approx -1453 \text{ kJ} \][/tex]

Thus, the reaction enthalpy for the given reaction under standard conditions is [tex]\(-1453\)[/tex] kJ.
Thank you for using this platform to share and learn. Don't hesitate to keep asking and answering. We value every contribution you make. Your questions find clarity at IDNLearn.com. Thanks for stopping by, and come back for more dependable solutions.