Acid-Base Theories Quiz

How does the Brønsted-Lowry theory improve upon the Arrhenius theory?

• It explains why acids always contain OH⁻.

• It includes reactions that only happen in gas phase.

• It defines acids as species that accept electron pairs.

• It defines acids as proton donors, even outside aqueous solutions.

What is the main difference between a Brønsted-Lowry base and a Lewis base?

• Lewis bases always produce OH⁻.

• Brønsted bases accept electrons; Lewis bases donate H⁺.

• Brønsted bases accept protons; Lewis bases donate electron pairs.

• There is no difference; both definitions are the same.

Why is water (H₂O) considered amphoteric under the Brønsted-Lowry theory?

• It has both hydrogen and oxygen.

• It can act as a proton donor or a proton acceptor.

• It can dissolve acids and bases equally.

• It always forms H⁺ and OH⁻.

Which acid-base theory best explains the formation of AlCl₄⁻ from AlCl₃ and Cl⁻?

• Arrhenius theory

• Brønsted-Lowry theory

• Lewis theory

• None of the theories explain this

Why does CH₃COOH qualify as an acid in all three acid-base theories?

• It produces OH⁻ in water.

• It contains a metal ion.

• It donates H⁺ and accepts electron pairs from bases.

• It only behaves as an acid in aqueous solutions.

In the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, which theories explain this behavior?

• Only Arrhenius, because OH⁻ is formed.

• Only Lewis, because NH₃ has lone pairs.

• Brønsted-Lowry and Lewis, because NH₃ accepts H⁺ and donates electron pairs.

• None, because NH₃ is not an acid.

A substance that donates an electron pair but does not donate a proton is best classified as:

• A Brønsted acid

• An Arrhenius base

• A Lewis base

• A neutral species

Why doesn't the presence of lone pairs automatically make a molecule behave as a base?

• Lone pairs must be donated in a reaction for base behavior.

• Lone pairs always make a molecule an acid.

• All molecules with lone pairs are Brønsted acids.

• Bases cannot contain lone pairs.

In the reaction Ag⁺ + 2NH₃ → [Ag(NH₃)₂]⁺, what role does Ag⁺ play?

• Brønsted base

• Arrhenius acid

• Brønsted acid

• Lewis acid

Which theory or theories best explain the following reactions? NH₃ + BF₃ → F₃B:NH₃

• Brønsted-Lowry and Arrhenius

• Only Lewis

• Arrhenius and Lewis

• Only Arrhenius