Advertisements
Advertisements
प्रश्न
A buffer solution contains 0.3 mol dm–3 NH4OH (Kb = 1.8 × 10–5) and 0.4 mol dm–3 NH4Cl. Calculate pOH of the solution.
Advertisements
उत्तर
Given: [Base] = 0.3 mol dm–3,
[Salt] = 0.4 mol dm–3,
Kb = 1.8 × 10–5 for the weak base
To find: pOH of the buffer solution
Formula: pOH = pKb + log10 `(["salt"])/(["base"])`
Calculation: pOH of basic buffer is given by Henderson-Hasselbalch equation:
pOH = pKb + log10 `(["salt"])/(["base"])`
pKb = – log10Kb
= – log10 (1.8 × 10–5) = 5 – log101.8
= 5 – 0.2553 = 4.7447
Substitution in the Henderson-Hasselbalch equation gives
pOH = 4.7447 + log10 `0.4/0.3` = 4.7447 + log10 1.333
= 4.7447 + 0.1248 = 4.8695
The pOH of the given buffer solution is 4.8695.
संबंधित प्रश्न
When NH4 Cl and NH4OH are added to a solution containing both, Fe3+ and Ca2+ ions, which ion is precipitated first and why?
A solution of NH4Cl and NH4OH acts as a buffer.
Choose the most correct answer:
Which of the Na following is a buffer solution?
Answer the following in one sentence :
How are basic buffer solutions prepared?
Answer the following in one sentence :
Classify the following buffers into different types :
Cu(OH)2 + CuCl2
In biochemical system, pH of blood in our body is maintained due to the following buffer:
The pKb of weak base BOH [Kb(BOH) = 1 × 10-5] will be ______.
Name the buffer which is used to maintained pH of 8 to 10 for precipitation of cations III A group in qualitative analysis.
Write the formula to calculate pH of buffer solution.
Define buffer solution.
Explain the types of buffer solutions.
Write one application of the following buffer:
`"HCO"_3^- + "H"_2"CO"_3`
Write one application of the following buffer:
NH4OH + NH4Cl
Which will make basic buffer?
Ksp of Al(OH)3 is 1 × 10−15 M. At what pH does 1.0 × 10−3 M Al3+ precipitate on the addition of buffer of NH4Cl and NH4OH solution?
On the basis of the equation \[\ce{pH}\] = – log \[\ce{[H+]}\], the \[\ce{pH}\] of 10–8 mol dm–3 solution of \[\ce{HCl}\] should be 8. However, it is observed to be less than 7.0. Explain the reason.
Assertion (A): A solution containing a mixture of acetic acid and sodium acetate maintains a constant value of \[\ce{pH}\] on addition of small amounts of acid or alkali.
Reason (R): A solution containing a mixture of acetic acid and sodium acetate acts as a buffer solution around \[\ce{pH}\] 4.75.
Assertion (A): An aqueous solution of ammonium acetate can act as a buffer.
Reason (R): Acetic acid is a weak acid and \[\ce{NH4OH}\] is a weak base.
Calculate the pH of buffer solution composed of 0.01 M weak base BOH and 0.02 M of its salt BA. [Kb = 1.8 × 10–5 for weak base]
What are buffer solutions?
Explain buffer action of sodium acetate-acetic acid buffer.
Calculate the pOH of a buffer solution formed from 0.3 M weak base and 0.45 M of its salt with strong acid [pKb = 4.7447].
A buffer solution is prepared by mixing 0.1 M ammonia solution and 0.25 M solution of NH4CI. What is the value of pKb to maintain its pOH at 6?
A buffer solution is prepared by mixing 0.01 М HCN and 0.02 M sodium cyanide. If pKa for HCN is 5.20, what is the pH of solution?
