chemistry module 5 equilibria

what is the mole fraction

the fraction of the total number of moles that each chemical in a reaction is responsible for

what is partial pressure

the part of the total pressure that each chemical in a reaction is responsible for

symbol for partial pressure

p

how to find mole fraction

number of moles of gas A / total number of moles of gas

how to find partial pressure

total pressure x mole fraction

expression for Kc

[C]^c [D]^d / [A]^a [B]^b

equation for kp

p(C)^c p(D)^d  /  p(A)^a p(B)^b

what is the effect of temperature on the value of Kc

For a reaction that is exothermic in the forward direction, increasing the temperature pushes the equilibrium from right to left

Therefore, the value of Kc will decrease as the ratio of [ products ] to [ reactants ] decreases

Conversely, if the temperature is raised in an endothermic reaction, the value of Kc will increase

what is the effect of temperature on the value of Kp

For a reaction that is exothermic in the forward direction, increasing the temperature pushes the equilibrium from right to left

Therefore, the value of Kp will decrease as the ratio of [ products ] to [ reactants ] decreases

Conversely, if the temperature is raised in an endothermic reaction, the value of Kp will increase

effect of pressure on the value of Kc

no effect

effect of pressure on the value of Kp

The value of Kp is not affected by any changes in pressure.

Changes in pressure cause a shift in the position of equilibrium to a new position which restores the value of Kp

This is analogous to what happens to Kc when you change concentration in an aqueous equilibrium; a shift restores equilibrium to a new position maintaining Kc