At 250 °c, the equilibrium constant kp for the reaction pcl5 (g) pcl3 (g) + cl2 (g) is 1.80. sufficient pcl5 is put into a reaction vessel to give an initial pressure of 2.74 atm at 250 °c. calculate the pressure of pcl5 after the system has reached equilibrium.
a. 1.50 atm
b. 1.24 atm
c. 4.24 atm
d. 0.94 atm
e. 1.12 atm

b. 1.24 atm

Explanation:

The chemical reaction for the decomposition of phosgene follows the equation:

At t = 0         2.74         0     0    

At    2.74-x           x      x

The expression for for the given reaction follows:

Putting values in above equation, we get:

So, the partial pressure for the components at equilibrium are:

Hence, the partial pressure of the at equilibrium is 1.24 atm

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y