1) Nitrosyl chloride (NOCl) decomposes at high temperature. The equation is
2 NOCl (g) -> 2 NO (g) + Cl2 (g) at 227oC
Using delta Ho = 81.2 kJ and delta So = 128 J/K, calculate the value of the equilibrium constant for this reaction.
I do not know how to start this problem or what formula I should use.
dGo = dHo - TdSo
Then dGo = -RTlnK
So for delta G= delta H - T delta S it would be delta G= 81200 J/K - 500K(128J/k)
This would equal 17200. Did I do this correctly so far before I move on?
To calculate the value of the equilibrium constant (K) for the given reaction, you can use the equation:
delta G = delta H - Tdelta S
where:
delta G is the change in Gibbs free energy
delta H is the change in enthalpy
T is the temperature in Kelvin
delta S is the change in entropy
In this case, you are provided with the values of delta H and delta S, so you can plug them into the equation and solve for delta G at the given temperature.
First, convert the temperature to Kelvin:
227oC + 273 = 500 K
Next, plug in the values:
delta G = 81.2 kJ - (500 K)(0.128 kJ/mol K)
Note that delta S is given in J/K, so you need to convert it to kJ/mol K by dividing by 1000.
Now, calculate:
delta G = 81.2 kJ - (500 K)(0.128 kJ/mol K)
= 81.2 kJ - 64 kJ/mol
The units of delta G will be in kJ/mol, which is consistent with the units of delta H. Now, you can use this value to calculate the equilibrium constant K.
The relationship between delta G and K is given by:
delta G = -RT ln(K)
where:
R is the gas constant (8.314 J/mol K)
T is the temperature in Kelvin
Since delta G is in kJ/mol and R is in J/mol K, you need to convert the units of delta G to J/mol by multiplying by 1000.
Now, rearrange the equation to solve for K:
K = e^(-delta G/RT)
Plug in the values:
K = e^(-(81.2 kJ)(1000 J/kJ) / ((8.314 J/mol K)(500 K)))
Evaluate the expression using a scientific calculator to get the numerical value of K.