Q: Which equation correctly represents the relationship between $$[\mathrm{H_3O^+}]$$ and $$[\mathrm{OH^-}] in $$aqueous solution at $$25^\circ\mathrm{C}$$?

$$[\mathrm{H_3O^+}] \times [\mathrm{OH^-}] = 1.0 \times 10$$^{-14}$$

Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout and the components are not visibly distinct.

Question 2

Which statement about electrolytes is correct?

Accepted Answer

Strong electrolytes dissociate completely into ions in solution.

Question 3

A solution is prepared by dissolving 0.5 mol of NaCl in enough water to make 1.0 L of solution. What is the molarity of NaCl in the solution?

Accepted Answer

$$0.5\ \mathrm{M}$$

Question 4

Which of the following is a correct statement about acids and bases according to the Arrhenius definition?

Accepted Answer

An acid produces $$\mathrm{H^+}$$ ions in water.

Question 5

Which of the following solutions has the highest concentration of ions?

Accepted Answer

A 1.0 M solution of NaCl (a strong electrolyte)

Question 6

If the concentration of $$\mathrm{H_3O^+} in a $$solution is $$1.0 	imes 10$$^{-4}$$\ \mathrm{M}$$, what is the pH of the solution?

Accepted Answer

$$4.0$$

Question 7

Which of the following is true about buffer solutions?

Accepted Answer

Buffers resist changes in pH when small amounts of acid or base are added.

Question 8

A solution contains $$0.10\ \mathrm{M}$$ acetic acid ($$\mathrm{CH_3COOH}) $$and $$0.10\ \mathrm{M}$$ sodium acetate ($$\mathrm{CH_3COONa}). $$What is the main function of this mixture?

Accepted Answer

To act as a buffer and maintain a relatively constant pH.

Question 9

Which equation correctly represents the relationship between $$[\mathrm{H_3O^+}]$$ and $$[\mathrm{OH^-}] in $$aqueous solution at $$25^\circ\mathrm{C}$$?

Accepted Answer

$$[\mathrm{H_3O^+}] 	imes [\mathrm{OH^-}] = 1.0 	imes 10$$^{-14}$$

Question 10

A buffer is made by mixing $$0.20\ \mathrm{mol} of a $$weak acid and $$0.20\ \mathrm{mol} of $$its conjugate base in $$1.0\ \mathrm{L} of $$solution. If a small amount of strong acid is added, what will happen to the pH?

Accepted Answer

The pH will decrease slightly, but remain close to its original value.

Question 11

Which of the following is a property of strong acids?

Accepted Answer

They completely dissociate in water to produce $$\mathrm{H^+}$$ ions.

Question 12

Which of the following is the correct formula for calculating the pH of a solution?

Accepted Answer

$$\mathrm{pH} = -\log[\mathrm{H_3O^+}]$$

Question 13

A solution has $$[\mathrm{OH^-}] = 1.0 	imes 10$$^{-8}$$\ \mathrm{M}. $$What is the pH of the solution?

Accepted Answer

$$6.0$$

Question 14

Which of the following statements about the dissociation of water is correct?

Accepted Answer

Water dissociates to produce equal concentrations of $$\mathrm{H_3O^+}$$ and $$\mathrm{OH^-}$$ ions.

Question 15

Which of the following is a Bronsted-Lowry acid?

Accepted Answer

A substance that donates a proton ($$\mathrm{H^+}) to $$another substance.

Question 16

Which of the following is the correct expression for the acid dissociation constant ($$K_a) $$for a weak acid $$HA$$?

Accepted Answer

$$K_a = \dfrac{[\mathrm{H^+}][\mathrm{A^-}]}{[\mathrm{HA}]}$$

Question 17

A solution has a pH of 2. What is the concentration of $$\mathrm{H_3O^+} in $$the solution?

Accepted Answer

$$1.0 	imes 10$$^{-2}$$\ \mathrm{M}$$

Question 18

Which of the following is true about the equivalence point in a titration of a strong acid with a strong base?

Accepted Answer

The number of moles of acid equals the number of moles of base.

Question 19

Which of the following is a property of weak bases?

Accepted Answer

They partially accept protons and only partially dissociate in water.

Question 20

A buffer solution is prepared using $$0.10\ \mathrm{mol} of$$ $$\mathrm{NH_3$}$$ and $$0.10\ \mathrm{mol} of$$ $$\mathrm{NH_4Cl} in$$ $$1.0\ \mathrm{L} of $$water. If $$0.01\ \mathrm{mol} of$$ $$\mathrm{HCl} is $$added, what will happen?

Accepted Answer

The pH will decrease slightly, but the buffer will resist large changes.

Study Guide: Solutions, Acids, and Bases (Chapters 9 & 11)

Guida di studio - Domande di pratica

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