36 reasonkp=(1.5*2)^(2)/(0.5*0.5)=36

Given information:
- Two moles of gas A2 are mixed with two moles of B2.
- The volume of the flask is 1 litre.
- At equilibrium, 0.5 moles of A2 are obtained.

To find:
The value of Kp for the reaction.

Explanation:

The given reaction is A2 + B2 ⇌ 2AB.

We can use the ideal gas law to determine the equilibrium constant Kp for this reaction.

The ideal gas law is given by: PV = nRT

Where:
P = pressure of the gas
V = volume of the flask
n = number of moles of gas
R = ideal gas constant
T = temperature in Kelvin

Since the volume of the flask is 1 liter, we can rewrite the ideal gas law equation as:

P = (nRT) / V

At equilibrium, the moles of A2 are 0.5 and the total moles of gas are 4 (2 moles of A2 + 2 moles of B2).

So, the partial pressure of A2 at equilibrium is:
PA = (0.5 moles / total moles) * Ptotal

Similarly, the partial pressure of B2 at equilibrium is:
PB = (0.5 moles / total moles) * Ptotal

The partial pressure of AB at equilibrium is:
PAB = (2 moles / total moles) * Ptotal

Since the number of moles and total pressure are constant, the ratio of the partial pressures is directly proportional to the ratio of the moles of each gas in the balanced equation.

Therefore, we can write the expression for Kp as:
Kp = (PAB^2) / (PA * PB)

Substituting the values, we get:
Kp = ((2/4)^2) / ((0.5/4) * (0.5/4))
= (1/4) / (1/16)
= 4

Hence, the value of Kp for the reaction is 4.