Acids and Bases

Question 1

Arrhenius theory

Answer 1

*Acids produce hydrogen ions (H+/H₃O+/hydronium ions) in aqueous solution.
*Bases produce hydroxide ions (OH-) in aqueous solution.

Question 2

Lowry-Brønsted theory

Answer 2

*An acid is a proton (H+ ion) donor
*A base is a proton (H+ ion) acceptor

Question 3

Strong acids

Answer 3

Ionised completely in water to form a high concentration of H₃O+ ions.
Examples of strong acids are hydrochloric acid, sulphuric acid and nitric acid

Question 4

Weak acids

Answer 4

Ionised incompletely in water to form a low concentration of H₃O+ ions.
Examples of weak acids are ethanoic acid and oxalic acid

Question 5

Strong bases

Answer 5

Dissociate completely in water to form a high concentration of OH- ions.
Examples of strong bases are sodium hydroxide and potassium hydroxide.

Question 6

Weak bases

Answer 6

Dissociate incompletely in water to form a low concentration of OH- ions.
Examples of weak bases are ammonia, calcium carbonate, potassium carbonate, calcium carbonate and sodium hydrogen carbonate

Question 7

Concentrated acids/bases

Answer 7

Contain a large amount (number of moles) of acid/bases in proportion to the volume of water

Question 8

Dilute acids/bases

Answer 8

Contain a small amount (number of moles) of acid/base in proportion to the volume of water

Question 9

Hydrolysis

Answer 9

The reaction of a salt with water

Question 10

Equivalent point of a titration

Answer 10

The point at which the acid/base has completely reacted with the base/acid

Question 11

Endpoint of titration

Answer 11

The point where the indicator changes colour