The Theory's of Acids and Bases

Kaleb Hill
Noah Joyner

Arrhenius Theory:

  • Acids are substances that release hydrogen ions, H+, when dissolved
  • Bases are substances that produce hydroxide ions, OH-, when dissolved
  • The neutralization reaction between an acid and a base is the reaction of the H+ and the OH-
  • Hydroniumion-H3O+
  • Due to polarity of water, unlikely that an h+ ion could exist in aqueous solution.

Revised arrhenius theory:

  • An acid increased the amount of H3O+ in a solution.
  • A neutralization reaction is the reaction of H3O+ and OH-.
  • Two problems with Arrhenius theory
  • o Salts: according to Arrhenius, only substances containing H+ or OH- can be acids or bases
  • o All other ionic compounds should be neutral but that’s not the case
  • Solvents: according to Arrhenius, acidity/basicity is a property of the solute. Therefore acids should always produce H+ , and bases OH- but that’s not the case.

Bronsted-Lowry Theory

  • Defines an acid as a substance that can donate H+
  • A base as a substance that can accept H+
  • An acid can behave as an acid only in the presence of a base that is willing to accept an H+

Conjugate acid-base pairs

  • Every acid has a corresponding base and vice versa
  • These corresponding acid-base pairs are called conjugate acids and conjugate bases
  • Some substances can act as B-L acids in some reactions and as B-L bases in others

Strong & Weak Acids

  • Strong acids will ionize completely when dissolved
  • Weak acids will only partially ionize when dissolved
  • Strong acids: hydrochloric acid, sulfuric acid, and nitric acid
  • Weak acids: acetic acid

Strong & Weak Bases

  • All group 1 hydroxides and some group 2 hydroxides are strong bases
  • o They dissociate partially
  • o Bronsted-Lowry bases are all weak
  • The electronegativity’s of the solute atoms and strengths of intramolecular bonds is what makes an acid or a base

The Theory's of Acids and Bases



Which are strong acids?

A. Hydrochloric Acid

B. Sulfuric Acid

C. Nitric Acid

D. All of the above

Which are weak acids?

A. Hydrochloric Acid

B. Sulfuric Acid

C. Acetic Acid

D. All of the above

Every Acid has a corresponding base.

A. True

B. False

Arrhenius had to ______ his theory to make it true

What were the two problems with Arrhenius's theory the first time?

A. Salts and solvents

B. Water and gas

C. Hydroxide and oxygen

D. None of the above

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