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What will be DeltaG for the reaction at ...

What will be `DeltaG` for the reaction at `25^(@)C` when partial pressures of reactants `H_(2), CO_(2),H_(2)O and CO` are 10, 20, 0.02 and 0.01 atm respectively. (Given : `G_(H_(2)O)^(@)=-"228.58 kJ, "G_(CO)^(@)=-"137,15 kJ, "G_(CO)^(@)=-"394.37 kJ"`.)

A

`+5.61kJ`

B

`-5.61 kJ`

C

`7.09 kJ`

D

`-8.13kJ`

Text Solution

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The correct Answer is:
To find the value of ΔG for the reaction at 25°C, we will follow these steps: ### Step 1: Write the balanced chemical equation The reaction can be represented as: \[ \text{H}_2(g) + \text{CO}_2(g) \rightleftharpoons \text{H}_2\text{O}(g) + \text{CO}(g) \] ### Step 2: Calculate ΔG° for the reaction Using the standard Gibbs free energy of formation values provided: - \( G^\circ_{H_2O} = -228.58 \, \text{kJ} \) - \( G^\circ_{CO} = -137.15 \, \text{kJ} \) - \( G^\circ_{H_2} = 0 \, \text{kJ} \) (as it is a standard state) - \( G^\circ_{CO_2} = -394.37 \, \text{kJ} \) The formula for ΔG° is: \[ \Delta G^\circ = \sum G^\circ_{\text{products}} - \sum G^\circ_{\text{reactants}} \] Substituting the values: \[ \Delta G^\circ = [G^\circ_{H_2O} + G^\circ_{CO}] - [G^\circ_{H_2} + G^\circ_{CO_2}] \] \[ \Delta G^\circ = [-228.58 + (-137.15)] - [0 + (-394.37)] \] \[ \Delta G^\circ = -365.73 + 394.37 = 28.64 \, \text{kJ} \] ### Step 3: Calculate the reaction quotient Q The reaction quotient Q is given by: \[ Q = \frac{P_{H_2O} \cdot P_{CO}}{P_{H_2} \cdot P_{CO_2}} \] Substituting the given partial pressures: - \( P_{H_2} = 10 \, \text{atm} \) - \( P_{CO_2} = 20 \, \text{atm} \) - \( P_{H_2O} = 0.02 \, \text{atm} \) - \( P_{CO} = 0.01 \, \text{atm} \) Calculating Q: \[ Q = \frac{(0.02)(0.01)}{(10)(20)} = \frac{0.0002}{200} = 1 \times 10^{-6} \] ### Step 4: Calculate ΔG using the formula The formula for ΔG is: \[ \Delta G = \Delta G^\circ + RT \ln Q \] Where: - \( R = 8.314 \, \text{J/(mol K)} \) (or \( 0.0831 \, \text{kJ/(mol K)} \)) - \( T = 298 \, \text{K} \) Calculating \( RT \ln Q \): \[ RT = 0.0831 \times 298 \approx 24.79 \, \text{kJ/mol} \] \[ \ln Q = \ln(1 \times 10^{-6}) \approx -13.8155 \] \[ RT \ln Q \approx 24.79 \times (-13.8155) \approx -342.5 \, \text{kJ} \] Now substituting back into the ΔG equation: \[ \Delta G = 28.64 + (-342.5) = -313.86 \, \text{kJ} \] ### Final Answer Thus, the value of ΔG for the reaction at 25°C is: \[ \Delta G \approx -313.86 \, \text{kJ} \]

To find the value of ΔG for the reaction at 25°C, we will follow these steps: ### Step 1: Write the balanced chemical equation The reaction can be represented as: \[ \text{H}_2(g) + \text{CO}_2(g) \rightleftharpoons \text{H}_2\text{O}(g) + \text{CO}(g) \] ...
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