Calculate the Kp

Question

At 459 K, this reaction has a Kc value of 0.0558.

X(g) + 2Y(g) --><--2Z(g)

calculate kp at 459K

(Pressure is in units of (atm)

Answer 1

K_p = K_c(RT)^Δn

With the equation above, and the temperature and chemical equation given, we can solve for K_p

K_p = (0.0558)*((0.0821 L*atm/mol*K)*(459 K))^-1

K_p = 0.00148

The reason the exponent (Δn), is -1 is because it is the difference between the number of moles of gas of products, and the number of moles of gas of reactants. In this case, it was 2 - 3 = -1. Also note that because pressure here is in units of atm, we had to use the gas constant that contained the unit of atm (0.0821 L*atm/mol*K) before performing our calculation.