Brønsted-Lowry Acids & Bases (College Board AP® Chemistry): Flashcards
0Still learning
Know0
Define Brønsted-Lowry acid.
Was this flashcard helpful?
Cards in this collection (14)
Define Brønsted-Lowry acid.
A species that donates a proton (H+) to another species in a chemical reaction.
In the reaction HCl + H2O → H3O+ + Cl-, HCl acts as a Brønsted-Lowry .......... and H2O acts as a Brønsted-Lowry .......... .
In the reaction HCl + H2O → H3O+ + Cl-, HCl acts as a Brønsted-Lowry acid and H2O acts as a Brønsted-Lowry base.
True or False?
The Brønsted-Lowry theory applies only to reactions in aqueous solution.
False.
The Brønsted-Lowry theory is not limited to aqueous reactions. It can be applied to acid-base reactions in the gas phase and other non-aqueous conditions.
Define amphiprotic.
A species that can act as both a Brønsted-Lowry acid (proton donor) and a Brønsted-Lowry base (proton acceptor) depending on the reaction conditions. Water is a key example.
In the reaction NH3 + H2O → NH4+ + OH-, how does water behave and why?
Water acts as a Brønsted-Lowry acid because it donates a proton (H+) to ammonia (NH3). This illustrates water's amphiprotic nature — it can donate or accept protons depending on its reaction partner.
True or False?
In the reaction CH3COOH + NH3 → CH3COO- + NH4+, water is involved as a reactant.
False.
This is a direct acid-base reaction between acetic acid (CH₃COOH) and ammonia (NH₃) with no water as a reactant. The Brønsted-Lowry theory allows for acid-base reactions without water.
Identify the Brønsted-Lowry acid and base in: H2SO4 (aq) + H2O (l) → HSO4- (aq) + H3O+ (aq)
Brønsted-Lowry acid: H2SO4 — it donates a proton to water.
Brønsted-Lowry base: H2O — it accepts the proton to become H3O+.
Define conjugate acid-base pair.
Two species related by the transfer of exactly one proton: the acid form has the extra proton; the base form has one fewer proton. They differ by exactly H+.
In the equilibrium CH3COOH + H2O ⇌ CH3COO- + H3O+, the conjugate base of CH3COOH is .......... and the conjugate acid of H2O is .......... .
In the equilibrium CH3COOH + H2O ⇌ CH3COO- + H3O+, the conjugate base of CH3COOH is CH3COO- and the conjugate acid of H2O is H3O+.
True or False?
The conjugate base of a strong acid is itself a strong base.
False.
The conjugate base of a strong acid is a weak base. Strong acids are good proton donors, so their conjugate bases have little tendency to accept protons back.
In the reaction HBr (aq) + H2O (l) → Br- (aq) + H3O+ (aq), what are the two conjugate acid-base pairs?
Pair 1: HBr (acid) and Br- (conjugate base)
Pair 2: H2O (base) and H3O+ (conjugate acid)
Each pair differs by exactly one proton.
Why can the relative strength of a conjugate acid or base be predicted from the strength of its partner?
Proton donation and acceptance are in competition. If a species is a strong acid, it releases protons readily, leaving a conjugate base with little tendency to recapture them — making it a weak base. The reverse applies to strong bases and their conjugate acids.
True or False?
Among the hydrohalic acids HF, HCl, HBr, and HI, HI is the strongest acid.
True.
HI has the longest, weakest H–I bond due to iodine's large atomic radius. A weaker bond makes proton donation easier, so HI is the strongest acid in the series.
A base accepts a proton to become a conjugate .......... ; an acid donates a proton to become a conjugate .......... .
A base accepts a proton to become a conjugate acid; an acid donates a proton to become a conjugate base.
Sign up to unlock flashcards
or