Question

In: Chemistry

The Ka of a weak acid is 1.48 x 10-5. Assuming the "x is small" approximation...

The Ka of a weak acid is 1.48 x 10-5. Assuming the "x is small" approximation is valid, what is the predicted pH of a 0.05 M solution of the weak acid? Provide your response to two decimal places.

Solutions

Expert Solution

                             HA ------------> H^+ (aq) + A^- (aq)

                I           0.05                 0                  0

               C            -x                   +x                 +x

              E            0.05-x               +x                +x

                   Ka   = [H+][A-]/[HA]

                 1.48*10^-5   = x*x/(0.05-x)

                1.48*10^-5 *(0.05-x) = x^2

                   x    = 0.000853

                 [H+]   = x = 0.000853M

                PH   = -log[H+]

                       = -log0.000853

                        = 3.069 >>>answer


Related Solutions

Weak Acid Ka Weak Base Kb CH3COOH (Acetic Acid) 1.8 X 10-5 NH3 (Ammonia) 1.76 X...
Weak Acid Ka Weak Base Kb CH3COOH (Acetic Acid) 1.8 X 10-5 NH3 (Ammonia) 1.76 X 10-5 C6H5COOH (Benzoic Acid) 6.5 X 10-5 C6H5NH2 (Aniline) 3.9 X 10-10 CH3CH2CH2COOH (Butanoic Acid) 1.5 X 10-5 (CH3CH2)2NH (Diethyl amine) 6.9 X 10-4 HCOOH (Formic Acid) 1.8 X 10-4 C5H5N (Pyridine) 1.7 X 10-9 HBrO (Hypobromous Acid) 2.8 X 10-9 CH3CH2NH2 (Ethyl amine) 5.6 X 10-4 HNO2 (Nitrous Acid) 4.6 X 10-4 (CH3)3N (Trimethyl amine) 6.4 X 10-5 HClO (Hypochlorous Acid) 2.9 X...
Chloropropionic acid, ClCH2CH2COOH is a weak monoprotic acid with Ka = 7.94 x 10-5 M. Calculate...
Chloropropionic acid, ClCH2CH2COOH is a weak monoprotic acid with Ka = 7.94 x 10-5 M. Calculate the pH at the equivalence point in a titration 34.8 mL of 1.09 M chloropropionic acid with 0.2 M KOH.
Chloropropionic acid, ClCH2CH2COOH is a weak monoprotic acid with Ka= 7.94 x 10-5 M. Calculate the...
Chloropropionic acid, ClCH2CH2COOH is a weak monoprotic acid with Ka= 7.94 x 10-5 M. Calculate the pH at the equivalence point in a titration 24.1 mL of 1.33 M chloropropionic acid with 0.3 M KOH.
A 25.0 mL sample of a 0.150 M weak acid, Ka = 4.6 x 10−5 ,...
A 25.0 mL sample of a 0.150 M weak acid, Ka = 4.6 x 10−5 , is titrated with 0.200 M NaOH. Calculate the pH when 10.0 mL of the base has been titrated into the acid.
A 100 mL solution of 0.100 M hydroxyacetic acid (Ka = 1.48 x 10-4 ) is...
A 100 mL solution of 0.100 M hydroxyacetic acid (Ka = 1.48 x 10-4 ) is titrated with 0.0500 M KOH. Answer the questions that follow; (a) What volume of KOH is required to reach the equivalence point? (b) What is the pH at the equivalence point? (c) Which indicator below would be suitable for determining the end point? Methyl yellow (pKa 3.1), chlorophenol red (pKa 6.2), thymol blue (pKa 8.9)
A. if the Ka of a monoprotic weak acid is 1.1 x 10^-6, what is the...
A. if the Ka of a monoprotic weak acid is 1.1 x 10^-6, what is the ph of a 0.21M solution of this acid? ph= B. Enough of a monoprotic acid is dissolved in water to produce a 0.0117M solution. The PH of the resulting solution is 2.57. Calculate the Ka for this acid. Ka= C.The Ka of a monoprotic weak acid is 7.73x10 ^-3. what is the percent ionization of a 0.106 M solution of this acid?
formic acid is a weak acid Ka= 1.9 x 10^-4 . Calculate the ph of a...
formic acid is a weak acid Ka= 1.9 x 10^-4 . Calculate the ph of a .50M solution of formic acid. what is the degree of ionization?
Lactic acid (HC3H5O3), a weak monoprotic acid with a Ka = 1.4 x 10-4, is titrated...
Lactic acid (HC3H5O3), a weak monoprotic acid with a Ka = 1.4 x 10-4, is titrated with KOH. If you have 50.0 mL of a 0.500 M HC3H5O3solution, calculate the pH after 150.0 mL of 0.250 M KOH have been added:
If a buffer solution is 0.160 M in a weak acid (Ka = 1.0 × 10-5)...
If a buffer solution is 0.160 M in a weak acid (Ka = 1.0 × 10-5) and 0.470 M in its conjugate base, what is the pH?
1.) Acetic acid is a weak monoprotic acid with Ka=1.8*10^-5. In an acid base titration, 100...
1.) Acetic acid is a weak monoprotic acid with Ka=1.8*10^-5. In an acid base titration, 100 mL of 0.100M acetic acid is titrated with 0.100M NaOH. What is the pH of the solution: a.)Before any NaOH is added b.)Before addition of 15.0mL of 0.100M NaOH c.)At the half-equivalence point d.)After addition of total of 65.0mL of 0.100M NaOH e.)At equivalence point f.)After addition of a total of 125.0mL of 0.100M NaOH
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT