HL IB Chemistry: Proton Transfer Reactions

A comprehensive set of 40 flashcards covering the critical concepts from the HL IB Chemistry topic of Proton Transfer Reactions, useful for exam preparation.

What is a Brønsted-Lowry acid?

A species that donates a proton (H+).

What is a Brønsted-Lowry base?

A species that accepts a proton (H+) using its lone pair of electrons.

What does the equilibrium of a Brønsted-Lowry acid and base imply?

It shows the transfer of a proton from the acid to the base.

Which gases can Brønsted-Lowry theory apply to?

It applies to reactions occurring in the gas phase as well as in aqueous solutions.

Identify the acid and base in the reaction: H2PO4- + H2O → HPO4^2- + H3O+.

H2PO4- is the acid, H2O is the base.

What is the equivalent concentration of a strong acid?

A strong acid dissociates almost completely in aqueous solutions.

What is the definition of a weak acid?

An acid that partially (or incompletely) dissociates in aqueous solutions.

What is a conjugate acid-base pair?

Two species that differ by a single proton (H+).

What is an amphiprotic species?

A species that can act both as a proton donor and a proton acceptor.

What defines a pH scale?

A logarithmic scale that indicates the acidity or alkalinity of a solution, usually ranging from 0 to 14.

How is pH calculated?

pH = -log[H+], where [H+] is the concentration of hydrogen ions.

Why is pH considered a logarithmic scale?

Each value is 10 times the value below it.

What happens to pH when an acidic solution is diluted?

The pH increases as the concentration of H+ ions decreases.

What is the ion product of water (Kw) at 298 K?

Kw = [H+][OH-] = 1.00 x 10^-14.

What characterizes strong bases?

Strong bases dissociate completely in aqueous solutions.

What differentiates weak acids from strong acids?

Weak acids establish an equilibrium, while strong acids dissociate completely.

How do changes in temperature affect the pH of water?

Increasing temperature decreases the pH, making water more acidic.

What are the products of a neutralization reaction?

An acid and a base react to form water and a salt.

Explain the enthalpy of neutralization.

It's the enthalpy change when an acid reacts with a base to form one mole of water.

How does the concentration of H+ ions affect electrical conductivity in acids?

Stronger acids with higher H+ concentrations conduct electricity better.

What happens to the pH when adding a strong acid to a metal?

The reaction is vigorous, producing gas due to higher H+ concentrations.

What is a buffer solution?

A solution that resists changes in pH upon addition of small amounts of acids or bases.

What is the role of a conjugate base in a buffer?

It reacts with added H+ to minimize changes in pH.

How are strong acids and bases related to ionization?

Stronger acids and bases have a higher degree of ionization.

What is a salt hydrolysis reaction?

It occurs when an ionic salt dissolves in water, interacting with ions to affect pH.

What is the significance of the equivalence point in titrations?

It marks the point where the number of moles of acid equals that of base.

Describe the pH at the equivalence point for strong acid-strong base titrations.

The pH will be approximately 7.

What distinguishes weak acid-strong base titrations from strong acid-strong base titrations?

The pH at the equivalence point will be greater than 7 for weak acid-strong base titrations.

What indicates a basic solution in terms of [H+] and [OH-]?

[OH-] is greater than [H+].

What defines the endpoint of a titration in relation to pH and pKa?

pH at endpoint matches pKa of the indicator used.

What is the Henderson-Hasselbalch equation?

pH = pKa + log([A-]/[HA]), used to calculate the pH of buffer solutions.

What brand of pH indicators usually change color at specific pH ranges?

Indicators like phenolphthalein change color around their pKa.

What are the typical applications for buffers?

Buffers are used in biological systems, chemical processes, and laboratory experiments to maintain stable pH.

Identify a factor that can greatly influence the effectiveness of a buffer.

Excessive addition of acids or bases can overwhelm the buffering capacity.

How does the presence of water molecules affect the acidity of metal ions in solution?

Highly charged metal ions can attract water molecules, creating complexes that can release protons.

What is the relationship between a strong acid and its conjugate base?

Strong acids yield weak conjugate bases.

How is K related to acid-base strength?

The larger the K value, the stronger the acid or base.

What is the concept of salt formation in acid-base reactions?

Salts form from neutralization reactions involving an acid and a base.