Buffer Solution

The buffer solution is able to maintain pH by some events, except ....

• the addition of a little acid

• dilution

• the addition of a excess acid

• the addition of a little base

• addition of water

The following mixture of solutions that form a buffer solution is ....

• 50 mL CH₃COOH 0,2 M and 50 mL NaOH 0,1 M

• 50 mL CH₃COOH 0,2 M and 100 mL NaOH 0,1 M

• 50 mL HCl 0,2 M and 100 mL NH₄OH 0,1 M

• 50 mL HCl 0,2 M and 100 mL NaOH 0,1 M

• 50 mL HCl 0,2 M and 50 mL NaOH 0,1 M

A buffer solution is made of mixture of aqueous ethanoic acid, CH₃COOH, wit aqueous potassium ethanoate, KCH₃COO. The equilibrium reaction takes place in buffer solution is:

CH₃COOH ↔ CH₃COO^- + H⁺

If small amount of HCl is added to that buffer solution, what reaction takes place at the buffer solution to resist change of pH?

• CH₃COOH + H⁺ ↔ CH₃COOH₂

• CH₃COO^- + H⁺ ↔ CH₃COOH

• CH₃COO^- + OH^- ↔ CH₃COO^2- + H₂O

• CH₃COOH + OH^- ↔ CH₃COO^- + H₂O

• CH₃COO^- + H₂O ↔ CH₃COOH + OH^-

The pH solution that consist of CH₃COOH 0.01 M and CH₃COONa 0.01 M with Ka = 10^-5 is . . .

• 4

• 5

• 6

• 8

• 9

Equilibrium reaction of carbon dioxide (CO₂) and hydrogencarbonate (HCO₃^-) ions in blood is one of the important buffer system that contribute to stabilise pH of the blood

CO₂(aq) + H₂O(l) ↔ H⁺(aq) + HCO₃^-(aq)

Which one take place on the buffer system when blood are slightly acidic than it would be normally ?

• equilibrium of the buffer system shifts to the right

• more hydrogencarbonate (HCO₃^-) ions are consumed in reaction with excess acid to produce more dissolved CO₂

• more dissolved CO₂ are consumed from the blood to remove excess acid and produce more hydrogencarbonate (HCO₃^-) ions

• No shift of the equilibrium take place on the buffer system