Acids and bases quest review

An example of a nonelectrolyte is

• C6H12O6(aq)

• K2SO4(aq)

• NaCl(aq)

• HCl(aq)

Answer explanation

C6H12O6 (glucose) is a nonelectrolyte because it does not dissociate into ions in solution. In contrast, K2SO4, NaCl, and HCl are electrolytes as they dissociate into ions, allowing them to conduct electricity.

Which of the following aqueous solutions is the best conductor of electricity?

• 0.10 M CH3OH

• 1.0 M CH3OH

• 0.10 M NaOH

• 1.0 M NaOH

Answer explanation

1.0 M NaOH is the best conductor because it fully dissociates into Na+ and OH- ions, increasing the number of charge carriers. In contrast, CH3OH (methanol) is a non-electrolyte and does not conduct electricity well.

Tags

NGSS.HS-PS1-5

Which substance, when dissolved in water, forms a solution that conducts an electric current?

• C2H5OH

• C6H12O6

• C12H22O11

• CH3COOH

Answer explanation

CH3COOH (acetic acid) ionizes in water, producing ions that allow the solution to conduct electricity. In contrast, C2H5OH (ethanol), C6H12O6 (glucose), and C12H22O11 (sucrose) do not produce ions and thus do not conduct electricity.

Which compounds can be classified as electrolytes?

• alcohols

• alkynes

• organic acids

• saturated hydrocarbons

Answer explanation

Organic acids can dissociate in water to produce ions, making them electrolytes. In contrast, alcohols, alkynes, and saturated hydrocarbons do not ionize in solution and therefore do not conduct electricity.

A substance is classified as an electrolyte because

• it has a high melting point

• it contains covalent bonds

• its aqueous solution conducts an electric current

• its aqueous solution has a pH value of 7

Answer explanation

A substance is classified as an electrolyte because its aqueous solution conducts an electric current, indicating the presence of ions that facilitate electrical conductivity.

According to the Arrhenius theory, a substance that is classified as an acid will always yield

• H+(aq)

• K+(aq)

• F-(aq)

• I-(aq)

Answer explanation

According to the Arrhenius theory, acids are defined as substances that produce H+(aq) ions in aqueous solution. Therefore, the correct answer is H+(aq), as it is the characteristic ion released by acids.

Unlike an acid, an aqueous solution of a base

• causes some indicators to change color

• conducts electricity

• contains more H+ ions than OH- ions

• contains more OH- ions than H+ ions

Answer explanation

An aqueous solution of a base contains more OH- ions than H+ ions, which is the defining characteristic of bases. This distinguishes them from acids, which have more H+ ions.

An Arrhenius base yields which ion as the only negative ion in an aqueous solution?

• hydride ion

• hydrogen ion

• hydronium ion

• hydroxide ion

Answer explanation

An Arrhenius base increases the concentration of hydroxide ions (OH-) in aqueous solution. Therefore, the only negative ion produced by an Arrhenius base is the hydroxide ion.

The only positive ion found in H2SO4(aq) is the

• ammonium ion

• hydronium ion

• hydroxide ion

• sulfate ion

Answer explanation

In H2SO4(aq), the only positive ion present is the hydronium ion (H3O+), formed when sulfuric acid donates a proton to water. The other options do not represent positive ions in this context.

How are HNO3(aq) and CH3COOH(aq) similar?

• They are Arrhenius acids and they turn blue litmus red.

• They are Arrhenius acids and they turn red litmus blue.

• They are Arrhenius bases and they turn blue litmus red.

• They are Arrhenius bases and they turn red litmus blue.

Answer explanation

HNO3(aq) and CH3COOH(aq) are both Arrhenius acids, meaning they produce H+ ions in solution. They also turn blue litmus paper red, indicating their acidic nature.