I need some help with this one please...
A+B ----> 2 D H= -765.3 kj S= 344 j/k
C ------> D H= 521 kj S= -171 j/k
calculate G at 298 K for A+B ------> 2C
I know I need to use the formula G= H-TS but I don't know how to get the numbers.
To calculate the Gibbs free energy (G) at 298 K for the reaction A+B → 2C, you can use the formula G = H - TS, where H represents the change in enthalpy, T is the temperature in Kelvin, and S represents the change in entropy.
Let's break down the steps to get the numbers:
1. Calculate the change in enthalpy (ΔH) for the reaction A+B → 2C. This can be done by summing the enthalpies of the products (2C) and subtracting the enthalpies of the reactants (A+B).
ΔH = [2(H of C) + 0] - [H of A + H of B]
The enthalpies for each substance can be found using the given values. For example, if the enthalpy of substance X is given as H(X), you would substitute the corresponding values into the equation.
2. Calculate the change in entropy (ΔS) for the reaction A+B → 2C. This can be done by summing the entropies of the products (2C) and subtracting the entropies of the reactants (A+B).
ΔS = [2(S of C) + 0] - [S of A + S of B]
Similar to step 1, substitute the given values into the equation for each substance.
3. Convert the temperature to Kelvin. If the given temperature is already in Kelvin, proceed to the next step. Otherwise, convert the temperature to Kelvin by adding 273.15 to the Celsius temperature.
T = 298 K
4. Substitute the calculated values (ΔH, ΔS, and T) into the formula:
G = ΔH - TΔS
Plug in the values you calculated in steps 1, 2, and 3 into the equation.
G = (ΔH calculated in step 1) - (T calculated in step 3) * (ΔS calculated in step 2)
By following these steps, you should be able to calculate the Gibbs free energy (G) at 298 K for the given reaction A+B → 2C.