What is the initial pH of a titration of 25.0 mL of 0.126 M NH3 with...

What is the initial pH of a titration of 25.0 mL of 0.126 M NH₃ with 0.287 M HCl? K_b = 1.8 x 10^-5SHOW WORK

a. 11.18

b. 7.00

c. 2.82

d. 1.04

e. 0.54

Solutions

Expert Solution

NH3 + H2O --------------> NH4+ + OH-

0.126 M 0 0

0.126-x x x

Kb = [NH4+] [OH-] /[NH3]

1.8 x 10^-5 = x.x / 0.126-x

Since x is very small, 0.126 -x = 0.126

Then,

1.8 x 10^-5 = x.x / 0.126

x = 0.0015 M

[OH-] = 0.0015 M

pOH = - log [OH-] = - log (0.0015) = 2.82

Hence,

pH = 14 -pOH= 14- 2.82= 11.18

Therefore,

Initial pH = 11.18

--------------------------------------

Ans = a

queen_honey_blossom answered 8 months ago

Next > < Previous

Related Solutions

What is the pH of the titration solution when 25.0 mL of .200 M aqueous formic...

What is the pH of the titration solution when 25.0 mL of .200 M aqueous formic acid, HCO2H, is titrated with 50.0 mL of 0.100 M aqueous potassium hydroxide, KOH? The Ka for formic acid is 1.8x10-4. A. 8.52 B. 7.00 C. 5.71 D. 8.29 E. 10.26

Calculate the pH of a titration with 25 mL of 0.1 M NH3 with 0.1 MHCl...

Calculate the pH of a titration with 25 mL of 0.1 M NH3 with 0.1 MHCl at the following volume points: 0, 10, 24.9, 25, 25.1, 40,50 mL

Consider the titration of 40.00 mL of 0.200 M NH3 with 0.500 M HCl. Calculate pH...

Consider the titration of 40.00 mL of 0.200 M NH3 with 0.500 M HCl. Calculate pH a) initially b) after addition of 5.00 mL of 0.500 M HCl c) at the half-neutralization point (halfway to equilvalence point) d) after the addition of 10.00 mL of 0.500 M HCl e) at the equivalence point

Calculate the pH for the titration of 100 mL of 0.10 M NH3, Kb = 1.8x10-5,...

Calculate the pH for the titration of 100 mL of 0.10 M NH3, Kb = 1.8x10-5, with 0.25 M HBr. a) Before any acid is added. pH= ?

Determine the pH during the titration of 35.9 mL of 0.280 M ammonia (NH3, Kb =...

Determine the pH during the titration of 35.9 mL of 0.280 M ammonia (NH3, Kb = 1.8×10-5) by 0.280M HCl at the following points. (Assume the titration is done at 25 °C.) Note that state symbols are not shown for species in this problem. (a) Before the addition of any HCl (b) After the addition of 13.9 mL of HCl (c) At the titration midpoint (d) At the equivalence point (e) After adding 51.7 mL of HCl

Calculate the pH for each of the following cases in the titration of 25.0 mL of...

Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.120 M pyridine, C5H5N(aq) with 0.120 M HBr(aq): Kb= 1.7x10^-7, so Ka must equal 5.88x10^-24 (a) before addition of any HBr, pH=? (b) after the addition of 12.5mL of HBr, pH=? (c) after the addition of 24.0mL of HBr, pH=? (d) after addition of 25.0mL of HBr, pH=? (e) after addition of 34.0mL of HBr, pH=?

Calculate the pH for each of the following cases in the titration of 25.0 mL of...

Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.120 M pyridine, C5H5N(aq) with 0.120 M HBr(aq): a) before addition of any HBr b) after addition of 12.5 mL of HBr c) after addition of 18.0 mL of HBr d) after addition of 25.0 mL of HBr e) after addition of 36.0 mL of HBr

Calculate the pH for each of the following cases in the titration of 25.0 mL of...

Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.250 M pyridine, C5H5N(aq) with 0.250 M HBr(aq): (a) before addition of any HBr (b) after addition of 12.5 mL of HBr (c) after addition of 14.0 mL of HBr (d) after addition of 25.0 mL of HBr (e) after addition of 30.0 mL of HBr Pyridine is a weak base with a Kb of 1.7× 10–9. It can react with strong acid to...

Calculate the pH for each of the following cases in the titration of 25.0 mL of...

Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.230A pyridine, C5H5N(aq) with 0.230M HBr(aq): a.) before addition of any HBr b.) after addition of 12.5 mL of HBr c.) after addition of 20.0 mL of HBr d.) after addition of 25.0 mL of HBr e.) after addition of 36.0 mL of HBr

Calculate the pH for each of the following cases in the titration of 25.0 mL of...

Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.150 M pyridine, C5H5N(aq) with 0.150 M HBr(aq): (a) before addition of any HBr (b) after addition of 12.5 mL of HBr (c) after addition of 14.0 mL of HBr (d) after addition of 25.0 mL of HBr (e) after addition of 30.0 mL of HBr

Subjects