Which of the following statements best defines le châtelier's principle?
a. it can be used to predict the effect of applying conditions of equilibrium on a chemical system.
b. it can be used to predict the effect of applying conditions of stress on a chemical system that is at equilibrium.
c. it can be used to predict the effect of increasing the reaction rate of a chemical system that is at equilibrium.
d. it can be used to predict the effect of a catalyst on a chemical system that is at equilibrium.

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.