Chapter 2

Brønsted–Lowry acids and bases, Reactions of Brønsted–Lowry acids and bases, Acid strength and pKa, Predicting the outcome of acid~~base reactions, Factors that determine acid strength, Common acids and bases, Aspirin, Lewis acids and bases [Smith, Organic Chemistry, 6e]

The Brønsted–Lowry definition describes acidity in terms of _______.

Protons

A Brønsted–Lowry acid is a proton ______. A Brønsted–Lowry base is a proton _________.

donor, acceptor

A Brønsted–Lowry acid must contain a _________.

Hydrogen atom

What is the symbol used for a general Brønsted–Lowry acid?

HA

Why does a Brønsted–Lowry base contain an “available” electron pair?

To form a bond to a proton

An ion that does not take part in a reaction and is opposite in charge to the ion that does take part in the reaction. It is also called a spectator ion.

Counterion

Which compound/s are Brønsted–Lowry acids: HBr, NH₃, CCl₄?

HBr

Which compounds are Brønsted–Lowry bases: CH3CH3, (CH3)₃CO⁻ , HC≡CH?

Loss of a proton from an acid forms its ______________.

conjugate base

Gain of a proton by a base forms its _______________.

conjugate acid

What is the conjugate acid of CH₃O−?

CH₃OH

What is the conjugate base of NH₃?

NH2^-

a. NH4+, HCl, (CH3)2C=OH⁺
b. Br^-, SO₄^-2, CH₃O^-

What is the conjugate acid of each base?

a. H2CO3
b. CH3(CH2)3NH2CH3
c. CH3OHCH3
d. CH3COOH

What is the conjugate base of each acid?

a. CO₃^-2
b. CH₃(CH₂)₂CH(NH₂)CH₃
c. [CH₃(CH₂)₂COO]^-
d. C₆H₁₁C≡C^-

Label each statement as True or False.

a. True
b. False
c. False
d. True
e. True

Label the acid and base, and the conjugate acid and base, in the following reactions. Use curved arrows to show the movement of electron pairs.

a. OH- < NH2- < CH3-
b. HC =- C- < CH2 = CH- <CH3-

What are four factors affect the acidity of HA

Element effects, inductive effects, resonance effects, and hybridization effects

Element effects

Across a row of the periodic table, the acidity of HA _________ as the electronegativity of A increases.

increases

Element effects

Down a column of the periodic table, the acidity of HA _______ as the size of A _________ .

increases, increases

It is the pull of electron density through σ bonds caused by electronegativity differences of atoms.

Induction effect

Inductive Effects
More ___________ stabilize regions of high electron density by an electron-withdrawing inductive effect.

electronegative atoms

More electronegative atoms stabilize regions of high electron density by an ___________ inductive effect

electron-withdrawing

Inductive Effects
The acidity of HA increases with the presence of ___________ groups in A.

electron-withdrawing