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**Problem**: Calculate the standard entropy change for the reaction2Mg(s) + O2(g) → 2MgO(s)using the data from the following table: Substance ?H?f (kJ/mol)?G?f (kJ/mol)S? [J/(K?mol)]Mg(s)0.000.0032.70O2(g)0.000.00205.0MgO(s)-602.0-569.627.00Express your answer to four significant figures and include the appropriate units.

###### FREE Expert Solution

We’re being asked to determine the **Standard entropy change **for the given reaction:

**2 Mg _{(s)} + O_{2(g}) → 2 MgO_{(s)}**

We can use the following equation to solve for **ΔS˚ _{rxn}**:

$\overline{){\mathbf{\Delta S}}{{\mathbf{\xb0}}}_{{\mathbf{rxn}}}{\mathbf{=}}{\mathbf{S}}{{\mathbf{\xb0}}}_{\mathbf{f}\mathbf{,}\mathbf{}\mathbf{prod}}{\mathbf{-}}{\mathbf{S}}{{\mathbf{\xb0}}}_{\mathbf{f}\mathbf{,}\mathbf{}\mathbf{react}}}$

Note that we need to *multiply each S˚ by the stoichiometric coefficient* since S˚ is in J/mol • K.

###### Problem Details

Calculate the standard entropy change for the reaction

2Mg(s) + O2(g) → 2MgO(s)

using the data from the following table:

**Substance**?

*H*?f (kJ/mol)?

*G*?f (kJ/mol)

*S*? [J/(K?mol)]Mg(s)0.000.0032.70O2(g)0.000.00205.0MgO(s)-602.0-569.627.00

Express your answer to four significant figures and include the appropriate units.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Entropy concept. You can view video lessons to learn Entropy Or if you need more Entropy practice, you can also practice Entropy practice problems .