Chemistry II

posted by .

Calculate the pH at the equivalence point in the titration of 50ml of 0.20 M methylamine (Kb=4.3*10^-4) with a 0.40 M HCL solution.

  • Chemistry II -

    How many mL HCl is needed? That's
    50 x 0.2/0.4 = 25.00 mL
    Total volume = 75.00 mL
    Total mols = 0.050 x 0.2 =0.01
    (salt at equivalence point) = 0.01/0.075L = approximately 0.13
    If we call methylamine just BNH2 then the salt will be BNH3^+ and it will hydrolyze as follows:

    ......BNH3^+ + H2O ==> H3O^+ + BNH2
    I.....0.13..............0........0
    C.......-x..............x........x
    E...-0.13-x.............x........x

    Ka for BNH3^+ = (Kw/Kb for BNH2) = (x)(x)/(0.13-x)
    Solve for x = (H3O^+) and convert to pH.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    Q.1 What will be the pH at the equivalence point during the titration of a 100 ml 0.2M solution of CH3COONa with 0.2M of solution of HCl?
  2. Chemistry

    Calculate the pH at the equivalence point for the titration of 0.120 M methylamine with 0.120 M HCl (kb of methyalamine is 5.0 x 10^-4)
  3. Chemistry!!

    Calculate the pH at the equivalence point for the titration of 0.180 M methylamine (CH3NH2) with 0.180 M HCl. The Kb of methylamine is 5.0× 10^–4.
  4. Analytical Chemistry

    Calculate the pH at the equivalence point for the titration of 0.160 M methylamine (CH3NH2) with 0.160 M HCl. The Kb of methylamine is 5.0× 10–4. Methylamine is a weak base and reacts with HCl to give the methylammonium ion. HCl …
  5. Chemistry

    Calculate the pH at the equivalence point for the titration of 0.200 M methylamine (CH3NH2) with 0.200 M HCl. The Kb of methylamine is 5.0× 10–4.
  6. chemistry

    CH3NH2(aq)+H2O(l)=>CH3NH3+(aq)+OH-(aq) Kb=4.4 x 10^-4 Methylamine, CH3NH2, is a weak base that reacts with water according to the equation above. A student obtains a 50.0 mL sample of a methylamine solution and determines the pH …
  7. AP Chemistry

    CH3NH2(aq)+H2O(l)=>CH3NH3+(aq)+OH-(aq) Kb=4.4 x 10^-4 Methylamine, CH3NH2, is a weak base that reacts with water according to the equation above. A student obtains a 50.0 mL sample of a methylamine solution and determines the pH …
  8. Chemistry

    Calculate the pH at the equivalence point for the titration of 0.180 M methylamine (CH3NH2) with 0.180 M HCl. The Kb of methylamine is 5.0× 10–4.
  9. CHemistry

    Calculate the pH at the equivalence point for the titration of 0.140 M methylamine (CH3NH2) with 0.140 M HCl. The Kb of methylamine is 5.0× 10–4.
  10. College Chemistry

    Calculate the pH at the equivalence point in the titration of 55.0 mL of 0.180 M methylamine(Kb = 4.4 × 10−4) with 0.330 M HCl.

More Similar Questions