1. State the Arrhenius definition of:
(a) an acid
(b) a base
2. The Arrhenius theory explains many acid-base reactions in aqueous solutions.
State one limitation of the Arrhenius theory and explain why this limitation led scientists to develop a new
acid-base theory.
3. Classify each substance below as an Arrhenius acid, Arrhenius base, or neither.
Substance Classification
HCl
NaOH
NH₃
H₂SO₄
Explain your answer for NH₃.
4. The following substances are dissolved separately in water.
•
HNO₃
•
KOH
•
CH₃COOH
(a) Which substances are Arrhenius acids?
(b) Which substance is an Arrhenius base?
(c) State the ions produced by each substance in water.
5. Complete the table.
Substance H⁺ produced? OH⁻ produced? Arrhenius Acid/Base/Neither
HCl
NaOH
NaCl
Ca(OH)₂
6. Hydrochloric acid reacts with sodium hydroxide.
HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)
(a) Identify the Arrhenius acid.
(b) Identify the Arrhenius base.
(c) State the ion produced by the acid.
(d) State the ion produced by the base.
1. State the Brønsted–Lowry definition of:
(a) an acid
(b) a base
2. In the reaction below,
HCl + H2O → H3O+ + Cl−
(a) Identify the Brønsted–Lowry acid.
(b) Identify the Brønsted–Lowry base.
(c) State the conjugate acid.
(d) State the conjugate base.
3. Consider the reaction:
NH3 + H2O ⇌ NH4+ + OH−
(a) Which substance donates a proton?
(b) Which substance accepts a proton?
(c) Identify the conjugate acid.
(d) Identify the conjugate base.
4. Explain why water acts as a Brønsted–Lowry acid in the reaction below.
NH3 + H2O ⇌ NH4+ + OH−
5. In the reaction
CH3COOH + H2O ⇌ CH3COO− + H3O+
(a) Identify the acid.
(b) Identify the base.
(c) Identify the conjugate acid.
(d) Identify the conjugate base.
6. The following reaction occurs in the gas phase.
NH3(g) + HCl(g) → NH4Cl(s)
(a) Explain how the Brønsted–Lowry theory explains this reaction.
(b) Identify the proton donor and proton acceptor.
(c) State why no water is required for this acid-base reaction.
7. The reaction below takes place.
HSO4− + H2O ⇌ SO42− + H3O+
(a) Identify the Brønsted–Lowry acid.
(b) Identify the Brønsted–Lowry base.
(c) State the conjugate acid.
(d) State the conjugate base.
(e) Explain why HSO₄⁻ is classified as an acid in this reaction.
8. Hydrogen carbonate ion, HCO₃⁻, can react in two different ways.
Reaction I: HCO3− + H2O ⇌ CO32− + H3O+
Reaction II: HCO3− + H2O ⇌ H2CO3 + OH−
(a) In Reaction I, identify the acid and base.
(b) In Reaction II, identify the acid and base.
(c) Explain what these reactions show about the properties of HCO₃⁻.
9.Four substances are involved in the following reaction.
HF + NH3 ⇌ F− + NH4+
Complete the table.
Species Role
HF
NH₃
F⁻
NH₄⁺
Then explain how proton transfer occurs during the reaction.