Question

If a buffer is prepared using 0.55 mol NH₄⁺ and 0.40 mol NH₃ in 1 liter of aqueous solution, is the buffering capacity of the solution great enough to maintain its pH if 30 g HI is added?

Select one:

a. Yes, the concentration of ammonia in the solution is great enough toneutralize the acid.

b. Yes, the concentration of ammonium ions in the solution is great enough toneutralize the acid.

c. No, the concentration of ammonia in the solution is not high enough toneutralize the acid.

d. No, the concentration of ammonium ions in the solution is not high enough toneutralize the acid.

e. No, a weak base cannot neutralize a strong acid.

Answer 1

Answer -In this given 0.55 mol NH₄⁺ and 0.40 mol NH₃ in 1 liter of aqueous solution and in this one if we added small amount of the the strong acid or base then there is no sudden change in the pH, but in this one there is added 30 g of HI means,

Moles of HI = 30 g / 127.91 g.mol^-1

                    = 0.234 moles

We have given the 0.40 moles of NH₃, so this moles of base are enough to neutralize the acid.

So answer for this one is about the buffering capacity of the solution great enough to maintain its pH if 30 g HI is added is –

a. Yes, the concentration of ammonia in the solution is great enough to neutralize the acid.