Chapter 16 Homework Flashcards

1
Q

In the following equation for the dissociation of sulfuric acid in water, identify the conjugate bases.
H2SO4(aq) + H2O(l0 -> HSO4-(aq) + H3O+(aq)

A

HSO4- and H2O

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2
Q

What is the hydrogen ion concentration of a solution with pH = −1?

A

1 × 10^1 M

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3
Q

Which of the following cannot act as a Brønsted-Lowry acid?

A

CO2

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4
Q

A simple dissociation reaction is written for each of the following acids. Which one is not correct?

A

Hydrochloric acid;

HCl(aq) <==> H+(aq) + Cl-(aq)

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5
Q

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

A

The H–F bond is very strong.

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6
Q

What is the [H3O+ ] in a solution with a pH of 2.34?

A

4.6 × 10^−3 M

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7
Q

What is the pOH if the hydronium ion concentration is 5.6 × 10−2 M?

A

12.75

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8
Q

What is the pH of a 0.10 M solution of the weak base methylamine (NH2CH3 )?
(Kb = 4.4 × 10^−4 )

A

11.82

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9
Q

A strong acid has a weak conjugate base because:

A

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.

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10
Q

Ammonia is a weak base with Kb = 1.8 × 10^−5. What is the Ka of the ammonium ion (NH4+ )?

A

5.6 × 10^−10

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11
Q

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.

A

1.3 × 10^−4

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12
Q

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?

A

5.6 × 10^−10

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13
Q

For any conjugate acid-base pair at 25°C, pKa + pKb equals all of the following except:

A

7

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14
Q

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

A

8.28

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15
Q

In which of the following is the curved arrow correctly drawn to indicate a Lewis acid-base reaction?

A

-

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16
Q

Which of the following is a Lewis acid?

A

BCl3

17
Q

Why is the following structure an acid?

A

The O–H bonds are easy to break.

18
Q

What is the pH if the hydroxide ion concentration is 3.14 × 10−7 M?

A

7.497

19
Q

What is the [OH − ] in a solution with a pOH of 12.12?

A

7.6 × 10^−13 M

20
Q

When calculating the pH of very dilute solutions, simply taking the negative log of the concentration of substance put into solution is likely to give incorrect results if the concentration is less than what?

A

10^−6