Question

50 ml of 0.2 m ammonium solution is treated with 25 ml of 0.1 m hcl if

Answer 1

Answer:

Brainly.in

What is your question?

1

Secondary School Chemistry 13 points

50 ml of 0.2 m ammonia solution is treated with 25 ml of 0.2 m hcl. If pkb of ammonia solution is 4.75, the ph of the mixture will be : (1) 3.75 (2) 4.75 (3) 8.25 (4) 9.25 50 ml of 0.2 m ammonia solution is treated with 25 ml of 0.2 m hcl. If pk b of ammonia solution is 4.75, the ph of the mixture will be

Ask for details Follow Report by Disai7254 12.12.2018

Answers

Me · Beginner

Know the answer? Add it here!

edwin555

edwin555 Ambitious

pH will be 9.25.

You need to consider the following calculations in details

the equation for the reaction is HCl (aq] + NH ₃(aq] → NH ₄⁺(aq] + Cl ⁻ (aq]

moles of NH3 aq is 50 x 0.2/1000 =0.01 moles

moles of HCl is 25 x 0.2/1000 = 0.005 moles

so limiting reactant is HCl

then moles of NH3 reacting completely is 0.01- 0.005 =0.005 moles

so the total volume will be 50 + 25 = 75ml

concentration = 0.005/0.075 = 0.07 M

Kb = 1.8 x 10^-5

pOH =pkb + log( [conjugate acid]/[weak base])

but we have equal concentrations of conjugate acid and weak base and thus its calculation amounts to 0

pOH= -log .8 x 10^-5 =4.74

Then pH= 14 - 4.74

pH= 9.25