Which of the following is a buffer system? Which of the following is a buffer system? H2CO3(aq) and KHCO3(aq) NaCl(aq) and NaOH(aq) H2O(l) and HCl(aq) HCl(aq) and NaOH(aq) NaCl(aq) and NaNO3(aq)

Explanation:

A buffer is defined as an aqueous mixture of a weak acid and its conjugate base or vice versa.

In the systems:

H₂CO₃(aq) and KHCO₃(aq): Carbonic acid, H₂CO₃, is a weak acid that, in solution with its conjugate pair, HCO₃⁻ make a buffer system.

NaCl(aq) and NaOH(aq): NaCl is a salt and NaOH is a strong base. Thus, this system is not a buffer system.

H₂O(l) and HCl(aq): Water is a solvent and HCl a strong acid. This is not a buffer system.

HCl(aq) and NaOH(aq): HCl is a strong acid and NaOH a strong base. This is not a buffer system.

NaCl(aq) and NaNO₃(aq): Both NaCl and NaNO₃ are salts and this system is not a buffer system.

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l