WorksheetsBuffer solution (qualitative)
Total questions: 15
Worksheet time: 1hrs 15mins
Which of the following statements ARE TRUE about buffer solution?
(you may choose more than one answer)
pH of buffer solution will never change despite addition of small amount of base or acid
Buffer can be made by mixing weak acid and salt of its conjugate base or by mixing weak base with salt of its conjugate acid
Buffer has acid and base components that can work specifically to resist pH change
the closer the ratio of concentration weak acid/base to the concentration of salt of its conjugate base/acid, the less effective the buffer to resist pH change
What statements CAN BE TRUE about acidic buffer?
(you may choose more than one answer)
It's made of a mixture of weak acid and salt of its conjugate base
Concentration of H+ ions in acidic buffer is greater than concentration of OH- ions which is present in the solution
Dilution of buffer by adding small amount of water doesn't change the pH of buffer solution
acidic buffer usually works effectively at pH range of above 7
What statements CAN BE TRUE about basic buffer?
(you may choose more than one answer)
basic buffer usually works effectively at pH range of above 7
It's made of a mixture of strong base and salt of its conjugate acid
adding small amount of strong acid to the solution of basic buffer can significantly alter the pH of the buffer solution
diluting solution of basic buffer cause pH of that solution to change drastically
a buffer solution is made of mixture of aqueous methanoic acid, HCOOH, with aqueous sodium methanoate, NaHCOO.
the equilibrium reaction takes place in buffer solution is :
HCOOH ↔ HCOO- + H+
small amount of NaOH is then added to that buffer solution.
What reaction take places at the buffer solution to resist change of pH caused by addition of base?
HCOOH + H+ → HCOOH2
HCOO- + H+ → HCOOH
HCOOH + OH- → HCOO- + H2O
HCOO- + OH- → COO2- + H2O
a buffer solution is made of mixture of aqueous ethanoic acid, CH3COOH, with aqueous potassium ethanoate, KCH3COO.
the equilibrium reaction takes place in buffer solution is :
CH3COOH ↔ CH3COO- + H+
small amount of HCl is then added to that buffer solution.
What reaction take places at the buffer solution to resist change of pH caused by addition of acid?
CH3COO- + H+ → CH3COOH
CH3COO- + OH- → CH2COO2- + H2O
CH3COOH + H+ → CH3COOH2
CH3COOH + OH- → CH3COO- + H2O
Which of the following mixture that may produce buffer solution to work at pH of below 7?
(you may choose more than one answer)
NaOH (in excess) + HCN
KOH + NaCH3COO
HCOOH + NaHCOO
KOH + HF (in excess)
HCOOH + CH3COOH
Which of the following mixture that may produce buffer solution to work at pH of above 7?
(you may choose more than one answer)
HCl + NH3 (in excess)
Mg(OH)2 + HF (in excess)
NaCN + HCN
NH3 + NH4NO3
H2SO4 (in excess) + NH3
Which of the following mixture that won't produce a buffer solution?
(you may choose more than one answer)
LiOH + LiF
HCl (in excess) + KOH
HNO3 (in excess) + NH3
NaOCl + NaOH
CH3COOH + Mg(CH3COO)2
Which of the following composition or mixture will, in general, form a solution of acidic buffer ?
(you may choose more than one answer)
strong acid + weak base (in excess)
strong base + weak acid (in excess)
weak acid + salt of its conjugate base
weak base + salt of its conjugate acid
strong acid (in excess) + strong base
Which of the following composition or mixture will, in general, form a solution of basic buffer ?
(you may choose more than one answer)
strong acid + weak base (in excess)
strong base + weak acid (in excess)
weak acid + salt of its conjugate base
weak base + salt of its conjugate acid
strong acid + strong base (in excess)
a buffer solution is made by mixing HA, a weak acid, with salts containing A- ions.
HA ↔ H+ + A-
a formula that can be used for the calculation of the pH of this buffer solution is
Which one actually take place when small amount of strong acid is added to a buffer solution?
(you may choose more than one answer)
the added acid will react with basic component of the buffer to minimize pH change caused by the former
the pH value of the solution slightly increase
the concentration of basic component and acid component of the buffer slightly decrease and slightly increase, respectively, after a new equilibrium is established
the numerical value of equilibrium constant of equilibirum involved in buffer solution change after addition of acid
Which one actually take place when small amount of strong base is added to a buffer solution?
(you may choose more than one answer)
the pH value of the solution doesn't change after the addition of base
the concentration of H+ ion in solution slightly decrease after the addition of base
the concentration of basic component and acid component of the buffer slightly increase and slightly decrease, respectively, after a new equilibrium is established
the added base is consumed by the acid component of the buffer to minimize pH change caused by the former
One of the buffer in blood plasma is a mixture of dihydrogenphospate ions (H2PO4-) and hydrogen phosphate (HPO42-) ions.
H2PO4- + H2O ↔ HPO42- + H3O+
which of the following pair acts as base-conjugate acid pair?
H2PO4- and HPO42-
H2O and H3O+
H2PO4- and H3O+
H2O and HPO42-
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-
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
