Question

1. An equilibrium mixture of CH.COH and CHCO,has a pH of 4.8. The equino equation is given below: CH3CO.H (aq) + H20 (1) = CH,CO2 (aq) + HO* (aq) Answer the following questions when the pH of the solution is adjusted to 2.8. 4. What happens to the concentration of H3O+ (aq) when pH changes from 4.8 to 2.87 b. In which direction does the equilibrium shift in the equation? c. What happens to the concentration of CH,CO2H (aq) when pH changes from 4.8 to 2.87 d. What happens to the concentration of CH3CO2 (aq) when pH changes from 4.8 to 2.8? 2. An equilibrium mixture of H2CO3 and HCO3 has a pH of 6.5. The equilibrium equation is given below: H:CO2 (aq) + H2O (1) HCO3+ (aq) + H30* (aq) Answer the following questions when the pH of the solution is adjusted to 8.5. a. What happens to the concentration of H3O+ (aq) when pH changes from 6.5 to 8.5? b. In which direction does the equilibrium shift in the equation? c. What happens to the concentration of H2CO3(aq) when pH changes from 6.5 to 8.5? d. What happens to the concentration of HCO3' (aq) when pH changes from 6.5 to 8.5?

Answer 1

Solution 1

Ang1 Equillibsrium has PA 4i8. EgM CH,COOH Cugp) + HyO(4) = CH,COO caq,) + Hyö' a) when H changes fram 4.8 do 2.8 . cuncentration * hydrogen don (H*) incruauses. Henes loucentration of Hgot increas. b) when Py cheunges do 2.8 that mmeans lonceulration of Ht don increuses. de-Chatelies's Principle :- Accoding to this principle , duhen an alterahion is mede to a bkystem duhich is in equillibrium, then the egquillibrium - chion to undo the effect of cheuge imþesed . bhift in that olire - luill Similerly uhen H* loncendration cincreased ie (Hyo"] inereut", the equillibrium uill bhift in Backward direction do undo the the increased toncen- -tration of Hgo* ion. Hence Buckward direchion. c) On ehanging the Pe to 2:8, the equillibrium will Shift in back wald dlirection and hence oce- -ntration of CH,COOH inereayes because moru and mori CHacoCH would form.

concentration of ording PH ato 2.8, d) On changing CH, coo® ion ccording to he- chablier's Prineiple equillibrium uill bhift backward and CHyCooO ions duill le lensumed uill deuriase because d Hence concent ration of CHCO0 ion deereases