Which of the following are conjugate acid-base pairs ?

conjugate acid-base pairs means there is a difference of ONE hydrogen atoms between the two pairs. From th elook of it, A,B,C,E

Adelaide Adrienne Ainsley Samantha Amelia Annabelle Anne Audrey Beatrice Blythe Evelyn Katelyn Cadence Catherine Charlotte Claire Colleen Fiona Leah Elizabeth Rosalie Erin

all of them are.

read on bronsted lowry acid base theory.

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at short:

The Arrhenius definition of an acid and a base:

Acids - substances that when dissolved in water release H+ ions

Bases - substances that when dissolved in water release OH- ions

The definition of an Arrhenius acid and base emphasizes the H+ and OH- ions in water

J.N. BrØnsted and T.M. Lowry proposed the following definition of acids and bases in 1923: an acid is a proton donor and base is a proton acceptor . In the general reaction,

B- + HA = HB + A-

B- is base (1)

HA is acid (1)

HB is acid (2)

A- is base (2)

a proton (H+) is transferred from HA to the anion, B-. HA is considered an acid because it can donate a proton while B- is a base as it can accept a proton. Because the reaction is reversible, HB and A- form a new acid and base, respectively. The HA / A- and the HB / B- combinations which differ by only a proton are called conjugate acid-base pairs.

H3O+ and H2O

H2O + H2O = H3O+ + OH-

H2O : acid(1)

H2O : base(1)

H3O+ is acid(2) conjugate to base (1)

OH- is base(2) conjugate to acid(1)

so H3O+ and H2O are conjugate acid-base pairs.

What enables water to act as either an acid or base is its ability to reversibly ionize as depicted in the reaction H2O + H2O = H3O+ + OH-

HCN and CN -

HCN + H2O = H3O+ + CN-

HCN is acid (1) giving a proton to become CN- (base)

H2O is base(1)

H3O+ is acid (2)

CN- is conjugate base from HCN

so, HCN and CN - are conjugate acid-base pairs.

HIO4 and IO4-

HIO4 + H2O = H3O+ + IO4-

HIO4 is acid (1) giving a proton to become IO4- (base)

H2O is base(1)

H3O+ is acid (2)

IO4- conjugate base from HIO4

so, HIO4 and IO4- are conjugate acid-base pairs.

KOH and OH -

KOH + H2O = KH2O+ + OH-

KOH base(1)

H2O acid(1)

KH2O+ acid(2)

OH- base(2)

KOH and OH - are conjugate acid-base pairs.

i am not sure about KOH + H2O = KH2O+ + OH- but i know KOH is a strong base.

(check other literature please)

NH4+ and NH3

NH4+ + OH- = NH3 + H2O

NH4+ is acid(1)

OH- is base(1)

NH3 is base(2)

H2O is acid(2)

NH4+ and NH3 are conjugate acid-base pairs.

challenging thing. look with google. it will help!

A B C & E

B, C, & E