Consider the equilibrium A(g) ⇀↽ 2 B(g) + 3 C(g) at 25◦C. When A is loaded into a cylinder at 9.13 atm and the system is allowed to come to equilibrium, the final pressure is found to be 16.89 atm. What is ∆G ◦ r for this reaction?

-14.60 kJ/mol

Explanation:

Equation for the reaction

A -------------->   2B   +   3C

The ICE Table is shown as:

                     A -------------->   2B     +      3C  

Initial             9.13                   0                0

Change         - x                     + 2x          + 3x

Equilibrium    9.13-x                2x              3x

(9.13-x)+2x+3x = 16.89

9..13 - x +5x  = 16.89

9.13+4x = 16.89

4x = 16.89-9.13

4x = 7.76

x =

x = 1.94

Equilibrium pressures are as follows:

A = 9.13 -x

= 9.13 - 1.94

= 7.19 atm

B = 2x

= 2 (1.94)

= 3.88 atm

C = 3x

= 3(1.94)

= 5.82 atm

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error