At 389K, this reaction has a Kc value of 0.0682. 2X(g) + 2Y(g) <-> Z(g) .. Calculate Kp at 389K. Kp=

this is what I did.. can somebody confirm or find any mistakes in my thought process?
Kp = Kc(R)(T)^Delta n
Delta n = (1)-(2+2) = -3
Kp = (0.0682)(0.08206)(398K)^-3 = 0.09678

i'm confused because I'm not sure if delta n is allowed to be negative. please help!

Thank you for proofreading!

Your thought process is mostly correct. However, there is a small mistake in the calculation of the value of Kp.

First, determine the change in moles (Δn) by comparing the sum of the stoichiometric coefficients of the products with the sum of the stoichiometric coefficients of the reactants:

Δn = (1) - (2+2) = -3

In this case, since the number of moles decreases, Δn is negative.

To calculate Kp, you can use the formula:

Kp = Kc * (RT)^Δn

where:
Kp = equilibrium constant in terms of partial pressures
Kc = equilibrium constant in terms of molar concentrations
R = ideal gas constant (0.08206 L·atm/(mol·K))
T = temperature in Kelvin

Substituting the given values:
Kc = 0.0682
R = 0.08206 L·atm/(mol·K)
T = 389 K
Δn = -3

Kp = 0.0682 * (0.08206 L·atm/(mol·K)) * (389 K)^(-3)

Calculating this expression, you should get the value for Kp.

Your thought process is mostly correct, but there is a small mistake. The value of Delta n should be positive in this case because there are fewer moles of gas on the product side compared to the reactant side. Let's go through the correct calculation:

Given information:
Kc = 0.0682
Temperature (T) = 389 K

The balanced equation is:
2X(g) + 2Y(g) <-> Z(g)

The reactant side has a total of 4 moles of gas (2 moles of X and 2 moles of Y), while the product side has only 1 mole of gas (Z). Therefore, Delta n = 1 - 4 = -3.

The ideal gas law expression for Kp is:
Kp = Kc * (RT)^Delta n

Now, let's substitute the values into the equation:
Kp = 0.0682 * (0.08206 * 389)^(-3)

Calculating this, we get:
Kp ≈ 0.0682 * 0.984^3 ≈ 0.0682 * 0.932 ≈ 0.0636

So, the correct value of Kp at 389 K is approximately 0.0636.

Yes, delta n may be negative and in this instance you are right that it is -3. However, you have parentheses in the wrong place. The formula is

Kp = Kc (RT)^delta n.
Kp = 0.0628(0.08206*398)^-3