Chapter 16 Homework Flashcards
In the following equation for the dissociation of sulfuric acid in water, identify the conjugate bases.
H2SO4(aq) + H2O(l0 -> HSO4-(aq) + H3O+(aq)
HSO4- and H2O
What is the hydrogen ion concentration of a solution with pH = −1?
1 × 10^1 M
Which of the following cannot act as a Brønsted-Lowry acid?
CO2
A simple dissociation reaction is written for each of the following acids. Which one is not correct?
Hydrochloric acid;
HCl(aq) <==> H+(aq) + Cl-(aq)
Hydrochloric acid (HCl), hydrobromic acid (HBr), and hydroiodic acid (HI) are all considered strong acids. Another hydrogen halide, hydrofluoric acid (HF) is a weak acid. Why is this the case, when HF has the greatest bond polarity of all these hydrogen halides?
Relative polarity: HI < HBr < HCl < HF
The H–F bond is very strong.
What is the [H3O+ ] in a solution with a pH of 2.34?
4.6 × 10^−3 M
What is the pOH if the hydronium ion concentration is 5.6 × 10−2 M?
12.75
What is the pH of a 0.10 M solution of the weak base methylamine (NH2CH3 )?
(Kb = 4.4 × 10^−4 )
11.82
A strong acid has a weak conjugate base because:
The conjugate base is a species that gave up a proton easily (as a strong acid), it is therefore going to be a poor proton acceptor.
Ammonia is a weak base with Kb = 1.8 × 10^−5. What is the Ka of the ammonium ion (NH4+ )?
5.6 × 10^−10
Lactic acid, CH3CHOHCO2H, is a monoprotic weak acid. A 0.10 M solution of lactic acid has a pH of 2.44. Calculate the equilibrium constant, Ka, for this acid.
1.3 × 10^−4
Acetic acid is a weak acid with an equilibrium constant of Ka = 1.8 × 10−5. In water, acetic acid partially dissociates to form acetate ions and hydronium ions.
What is Kb for the acetate ion?
5.6 × 10^−10
For any conjugate acid-base pair at 25°C, pKa + pKb equals all of the following except:
7
Aniline, (C6H5NH2 ) is a weak base widely used in the production of many brightly colored dyes. What is the pH of a 1.0 × 10^−2 M aniline solution? Use Kb = 3.8 × 10^−10
8.28
In which of the following is the curved arrow correctly drawn to indicate a Lewis acid-base reaction?
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