Question 1

Nitric acid is a strong acid,ammonium hydroxide is a weak base,and ammonium nitrate is a soluble salt.Which of the following is the net ionic equation for the reaction? HNO₃(aq)+ NH₄OH(aq)→ NH₄NO₃(aq)+ H₂O(l)

Accepted Answer

The net ionic equation includes only the species that undergo a chemical reaction. In this reaction, H+ ions from nitric acid react with OH- ions from ammonium hydroxide to form water and ammonium ions (NH4+), which does not participate in the actual reaction. The net ionic equation, therefore, is: H+ + OH- → H2O. Choice C shows the correct net ionic equation that represents the chemical reaction that occurs in the given reaction.

Question 2

Nitric acid is a strong acid,sodium hydroxide is a strong base,and sodium nitrate is a soluble salt.Which of the following is the net ionic equation for the reaction? HNO₃(aq)+ NaOH(aq)→ NaNO₃(aq)+ H₂O(l)

Accepted Answer

The net ionic equation for the reaction between a strong acid (HNO₃) and a strong base (NaOH) involves the hydrogen ion (H+) from the acid reacting with the hydroxide ion (OH-) from the base to form water (H₂O). This is represented by choice A: H+(aq) + OH-(aq) → H₂O(l). Sodium nitrate (NaNO₃) remains in solution as its constituent ions, Na+ and NO₃-, and does not appear in the net ionic equation.

Question 3

Sodium hydroxide is a strong base and ammonium hydroxide is a weak base.Which of the following correctly portrays aqueous solutions of the two bases?

Accepted Answer

Sodium hydroxide (NaOH) is a strong base, meaning it completely dissociates into Na+ and OH- ions in aqueous solution. Ammonium hydroxide (NH₄OH), being a weak base, does not completely dissociate in water and is often represented in its undissociated form, NH₄OH, in aqueous solution.

Question 4

Which of the following solutions is amphiprotic?

Accepted Answer

An amphiprotic substance is one that can act as both a Bronsted-Lowry acid and base. 
H₂CO₃ (carbonic acid) can donate a proton (act as an acid) but cannot accept a proton (act as a base), so it is not amphiprotic. 
Na₂CO₃ (sodium carbonate) has no available protons to donate or accept, so it is not amphiprotic. 
NaHCO₃ (sodium bicarbonate), on the other hand, can donate a proton to become HCO₃⁻ (bicarbonate ion) and can also accept a proton to become CO₃²⁻(carbonate ion). Therefore, it can act as both an acid and a base and is an amphiprotic solution.

Question 5

If a drain cleaner solution is a strong electrolyte,which of the following must be true?

Accepted Answer

A strong electrolyte is a substance that is highly ionized when dissolved in water. Therefore, if a drain cleaner solution is a strong electrolyte, it must be highly ionized.

Question 6

Which of the following in aqueous solution is a weak electrolyte?

Accepted Answer

H₂CO₃ (carbonic acid) is a weak electrolyte because it only partially ionizes in water, producing H⁺ and HCO₃⁻ ions, but not to a significant extent. LiOH (lithium hydroxide) and NH₄Cl (ammonium chloride) are strong electrolytes, fully dissociating into ions when dissolved in water. Therefore, the only weak electrolyte in the options given is choice A, H₂CO₃.

Question 7

Which of the following aqueous solutions is slightly ionized?

Accepted Answer

All of the options listed (weak acid, weak base, and very slightly soluble salt) describe substances that, when dissolved in water, are only slightly ionized, meaning they do not fully dissociate into ions.

Question 8

What is the pH of an aqueous solution whose hydrogen ion concentration is 1 M?

Accepted Answer

The pH of a solution is calculated using the formula pH = -log[H+], where [H+] is the concentration of hydrogen ions in moles per liter. For a concentration of 1 M, the pH is -log(1) = 0.

Question 9

Acetic acid is a weak acid,ammonium hydroxide is a weak base,and ammonium acetate is a soluble salt.Which of the following is the net ionic equation for the reaction? HC₂H₃O₂(aq)+ NH₄OH (aq)→ NH₄C₂H₃O₂(aq)+ H₂O(l)

Accepted Answer

The answer of Acetic acid is a weak acid,ammonium hydroxide...

Question 10

Which of the following is true if the pH of a solution decreases from 5 to 2?

Accepted Answer

A decrease in pH indicates an increase in [H+] concentration, as pH and [H+] are inversely related. Therefore, option A is correct. Kw, the ionization constant of water, remains constant at a given temperature and is not affected by a change in pH. Therefore, options C and D are incorrect. Option B is incorrect because a decrease in pH means that the [H+] concentration has increased, not decreased.

Question 11

Hydrochloric acid is a strong acid and acetic acid is a weak acid.Which of the following correctly portrays aqueous solutions of the two acids?

Accepted Answer

Hydrochloric acid (HCl) is a strong acid and dissociates completely in water into H+ and Cl- ions, while acetic acid (HC2H3O2) is a weak acid and does not dissociate completely, remaining mostly in its molecular form in aqueous solution.

Question 12

What is the hydrogen ion concentration of an aqueous solution having a pH of 0?

Accepted Answer

The pH of 0 indicates that the solution is very acidic, and the hydrogen ion concentration is very high. The pH scale is logarithmic, so a pH of 0 corresponds to an H+ concentration of 1 M. Therefore, choice C is correct. Choices A, B, and D are incorrect.

Question 13

Which of the following aqueous solutions is highly ionized?

Accepted Answer

All of the options listed (strong acid, strong base, and soluble salt) describe substances that, when dissolved in water, dissociate almost completely into ions, making their aqueous solutions highly ionized.

Question 14

What is the color of methyl red indicator at pH 5,the midpoint at which red and yellow are in equal concentration?

Accepted Answer

Methyl red indicator turns orange at pH 5, which is the midpoint at which red and yellow are in equal concentration.

Question 15

Which of the following solutions is amphiprotic?

Accepted Answer

Na₂HPO₄(aq) is amphiprotic because it can act both as an acid (donating a proton to form Na₃PO₄) and as a base (accepting a proton to form NaH₂PO₄).

Question 16

What is the color of bromthymol blue indicator at pH 7,the midpoint at which yellow and blue are in equal concentration?

Accepted Answer

Bromthymol blue has a pH range of 6.0 (yellow) to 7.6 (blue). At pH 7, which is the midpoint of this range, the indicator appears green.

Question 17

Acetic acid is a weak acid,potassium hydroxide is a strong base,and potassium acetate is a soluble salt.Which of the following is the net ionic equation for the reaction? HC₂H₃O₂(aq)+ KOH(aq)→ KC₂H₃O₂(aq)+ H₂O(l)

Accepted Answer

The net ionic equation shows only the species that are directly involved in the reaction. The spectator ions are removed. In this case, the spectator ions are K+ and Cl-. So, the net ionic equation is HC₂H₃O₂(aq)+ OH-(aq)→ C₂H₃O₂-(aq)+ H₂O(l). Choice D is the only one that matches this net ionic equation.

Question 18

Lithium nitrate is a soluble salt and silver iodide is a very slightly soluble salt.Which of the following correctly portrays aqueous solutions of the two salts?

Accepted Answer

Lithium nitrate (LiNO₃) is soluble in water and dissociates completely into Li⁺ and NO₃⁻ ions in solution, while silver iodide (AgI) is very slightly soluble, meaning it largely remains as a solid (s) in an aqueous solution.

Question 19

Which of the following is true if the pH of a solution increases from 2 to 5?

Accepted Answer

The pH scale is logarithmic, meaning that each increase or decrease in pH by one unit represents a tenfold increase or decrease in [ H+ ] concentration.

When the pH of a solution increases from 2 to 5, it means that the solution becomes less acidic and more basic. This indicates that the [ H+ ] concentration has decreased, and therefore Choice B is correct.

Choices C and D are not affected by changes in pH, as they are related to the ionization constant of water (Kw), which remains constant in aqueous solutions.

Choice A is incorrect because as the pH increases, the [ H+ ] concentration decreases.

Question 20

Which of the following in aqueous solution is a strong electrolyte?

Accepted Answer

KOH(aq) is a strong electrolyte because it completely dissociates into K+ and OH- ions in aqueous solution. H₃PO₄(aq) is a weak electrolyte because it only partially dissociates into H+ and H₂PO₄- ions. PbCl₂(s) is a solid and cannot be an electrolyte in aqueous solution. Therefore, the answer is B, KOH(aq).

Quiz 14: Acids and Bases

Nitric acid is a strong acid,ammonium hydroxide is a weak base,and ammonium nitrate is a soluble salt.Which of the following is the net ionic equation for the reaction? HNO₃(aq) + NH₄OH(aq) → NH₄NO₃(aq) + H₂O(l)

Nitric acid is a strong acid,sodium hydroxide is a strong base,and sodium nitrate is a soluble salt.Which of the following is the net ionic equation for the reaction? HNO₃(aq) + NaOH(aq) → NaNO₃(aq) + H₂O(l)

Sodium hydroxide is a strong base and ammonium hydroxide is a weak base.Which of the following correctly portrays aqueous solutions of the two bases?

Which of the following solutions is amphiprotic?

If a drain cleaner solution is a strong electrolyte,which of the following must be true?

Which of the following in aqueous solution is a weak electrolyte?

Which of the following aqueous solutions is slightly ionized?

What is the pH of an aqueous solution whose hydrogen ion concentration is 1 M?

Acetic acid is a weak acid,ammonium hydroxide is a weak base,and ammonium acetate is a soluble salt.Which of the following is the net ionic equation for the reaction? HC₂H₃O₂(aq) + NH₄OH (aq) → NH₄C₂H₃O₂(aq) + H₂O(l)

Which of the following is true if the pH of a solution decreases from 5 to 2?

Hydrochloric acid is a strong acid and acetic acid is a weak acid.Which of the following correctly portrays aqueous solutions of the two acids?

What is the hydrogen ion concentration of an aqueous solution having a pH of 0?

Which of the following aqueous solutions is highly ionized?

What is the color of methyl red indicator at pH 5,the midpoint at which red and yellow are in equal concentration?

Which of the following solutions is amphiprotic?

What is the color of bromthymol blue indicator at pH 7,the midpoint at which yellow and blue are in equal concentration?

Acetic acid is a weak acid,potassium hydroxide is a strong base,and potassium acetate is a soluble salt.Which of the following is the net ionic equation for the reaction? HC₂H₃O₂(aq) + KOH(aq) → KC₂H₃O₂(aq) + H₂O(l)

Lithium nitrate is a soluble salt and silver iodide is a very slightly soluble salt.Which of the following correctly portrays aqueous solutions of the two salts?

Which of the following is true if the pH of a solution increases from 2 to 5?

Which of the following in aqueous solution is a strong electrolyte?