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1- What is the pH of a 0.25 M aqueous solution of C2H5NH3Cl? 2- What would be th

ID: 508699 • Letter: 1

Question

1-

What is the pH of a 0.25 M aqueous solution of C2H5NH3Cl?

2-

What would be the pH of a buffer solution composed of equimolar amounts of C6H5NH3ClO4 and C6H5NH2 ?

3-

What is the predominate species present in a solution of 0.10 M H2C6H6O6 at a pH of 4.5?

4- Is the pH at the equivalence point in the titration of 0.10 M HC2H3O2 with 0.10 M NaOH acidic, basic, or neutral? Explain your answer.

5- What would be present in a flask containing a saturated solution of copper(II) hydroxide, Cu(OH)2?

6.4 x 10

Explanation / Answer

1)

CH3NH3Cl is the salt of weak base and strong acid.

pKb = -log Kb

pKb = 3.19

pH = 7 - 1/2 [pKb + log C]

pH = 7 - 1/2 [3.19 + log 0.25 ]

pH = 5.71

2)

Kb = 4.3 x 10^-10

pKb = 9.37

salt and base concentrations are same

pH = 14 - {pKb + log (salt / base)}

pH =14 - {9.37 + log (1/1)}

pH = 4.63