Chem Unit 8 - Acids and Bases (Kognity R3.1)

What is the Brønsted-Lowry definition of an acid?

An acid is defined as a proton donor.

What is the Brønsted-Lowry definition of a base?

A base is defined as a proton acceptor.

What ions do hydrogen ions become in aqueous solution?

Hydrogen ions become hydronium ions, H3O+ in aqueous solution.

What distinguishes an alkali from a base?

An alkali is a base that is soluble in water and produces hydroxide ions (OH-) when dissolved.

What are amphoteric substances?

Substances that can act as both acids and bases.

Name one amphiprotic substance.

Water (H2O) is an example of an amphiprotic substance.

What happens when hydrogen chloride (HCl) dissolves in water?

HCl donates a proton to water, making HCl an acid and water a base.

What are common strong acids?

Common strong acids include HCl, H2SO4, and HNO3.

What is the formula to calculate pH?

pH = -log[H+].

What does a lower pH indicate about a solution?

A lower pH indicates that the solution is more acidic.

What is the ionic product of water at 298K?

The ionic product of water is 1×10^-14 mol2 dm-6.

How can you distinguish strong acids from weak acids in terms of electrical conductivity?

Strong acids have high electrical conductivity, while weak acids have low electrical conductivity.

What is the general structure of a dissociation reaction for a weak acid?

HA(aq) ⇌ H+(aq) + A–(aq).

What is produced during a neutralization reaction?

A salt and water are produced during a neutralization reaction.

What is the equivalence point in titration?

The equivalence point is reached when a stoichiometric volume of alkali has been added to neutralize the acid.

How does the pH behave at the equivalence point of strong acid-strong base titrations?

The pH at the equivalence point is typically around 7.

What is the relation between Ka and Kb for conjugate acid-base pairs?

Ka × Kb = Kw.

What happens to the pH of salt solutions formed from weak acids and strong bases?

They typically have a pH greater than 7 and are basic salts.

What happens to the pH of salt solutions formed from strong acids and weak bases?

They typically have a pH less than 7 and are acidic salts.

What is a buffer solution?

A buffer solution resists changes in pH when acids or bases are added.

What is the role of a weak acid in a buffer solution?

A weak acid provides the necessary equilibrium to resist changes in pH.

What formula is used to calculate the pH of a basic buffer solution?

pH = pKa + log10([A-]/[HA]).

Explain the significance of the half-equivalence point in titrations.

At the half-equivalence point, pH = pKa, indicating the concentration of the weak acid equals that of its conjugate base.

What is the general behavior of a weak acid in a solution when compared to a strong acid?

Weak acids partially dissociate, while strong acids completely dissociate.

What does a color change in an acid-base indicator signify?

It indicates a change in the pH of the solution, depending on the concentration of H+ or OH- ions.

How does the strength of an acid relate to its conjugate base?

Strong acids have weak conjugate bases, whereas weak acids have strong conjugate bases.

What is the pOH of a solution related to?

The pOH is related to the concentration of hydroxide ions [OH−] in the solution.