calculate delta G at 298 K when 5.0 atm H2 and 3.0 atm of CO2 are converted to methanol.
I know you can calulate for Q and use that but how do you do the calculation when you don't have the atm for the final product.
To calculate ΔG at 298 K when 5.0 atm of H2 and 3.0 atm of CO2 are converted to methanol, we need to use the concept of reaction quotient (Q). However, you mentioned that you don't have the atm for the final product. In such cases, we can still calculate ΔG using an alternative approach known as the standard Gibbs free energy change (ΔG°).
Here's how you can proceed:
1. Write the balanced chemical equation for the reaction:
CO2 + 3H2 ⇌ CH3OH
2. Determine the standard Gibbs free energy change for the reaction (ΔG°):
ΔG° = [nΔGf°(CH3OH)] - [mΔGf°(CO2)] - [lΔGf°(H2)]
Where:
n = Stoichiometric coefficient of CH3OH in the balanced equation
m = Stoichiometric coefficient of CO2 in the balanced equation
l = Stoichiometric coefficient of H2 in the balanced equation
ΔGf° = Standard Gibbs free energy of formation for each species involved in the reaction.
3. Look up the standard Gibbs free energy of formation values (ΔGf°) for each species involved in the reaction. You can find these values in thermodynamic tables or reference books. Make sure to use values at 298 K.
4. Substitute the values into the equation and calculate ΔG°.
Note that ΔG° gives you the change in Gibbs free energy when reactants are converted to products under standard conditions (1 atm and 298 K).
Please follow the above steps to calculate ΔG° for the given reaction.