Everything Science Grade 11

8.1 CHAPTER 8. TYPES OFREACTIONS

H 2 O + NH 3 NH+ 4 + OH−

acid 1 base 2 acid 2 base 1

conjugate pair

conjugate pair

DEFINITION: Conjugate acid-base pair

The term refers to two compounds that transforminto each other by the gain or loss

of a proton.

See video: VPjpw at http://www.everythingscience.co.za

Exercise 8 - 1

In each of the followingreactions, label the conjugate acid-base pairs.

1. H 2 SO 4 + H 2 O� H 3 O++ HSO− 4


2. NH+ 4 + F−� HF + NH 3


3. H 2 O + CH 3 COO−� CH 3 COOH + OH−


4. H 2 SO 4 + Cl−� HCl + HSO− 4

More practice video solutions or help at http://www.everythingscience.co.za

(1.) 00zk

Acid-base reactions ESBBY

When an acid and a base react, they neutralise each other to form a salt. If the base contains hydrox-
ide (OH−) ions, then water will also be formed. The word salt is a general term whichapplies to the
products of all acid-basereactions. A salt is a product that is made up ofthe cation from a base and
the anion from an acid.When an acid reacts with a base, they neutralise each other. In other words,
the acid becomes less acidic and the base becomes less basic. Look atthe following examples:

1. Hydrochloric acid reacts with sodium hydroxide to form sodium chloride (the salt) and water.
   Sodium chloride is made up of Na+cations from the base (NaOH) and Cl−anions from the acid
   (HCl).

HCl + NaOH→ H 2 O + NaCl