Acids and Bases

Question 1

What is a Bronsted-Lowry acid?

Answer 1

Acids are proton donors (donate H+ ions)

Question 2

What is a Bronsted-Lowry base?

Answer 2

Bases are proton acceptors (accepts H+ ions)

Question 3

What is an alkali?

Answer 3

A soluble base that produces OH- ions when added to water.

Question 4

Common strong acids names and formulas (give three)

Answer 4

Hydrochloric acid - HCl, Sulfuric acid - H2SO4, Nitric acid - HNO3

Question 5

Common strong base names and formulas (give two)

Answer 5

Sodium hydroxide - NaOH (or any other metal hydroxide), Oxide ion - (O)2-

Question 6

Common weak acids names and formulas (give two)

Answer 6

Ethanoic acid - CH3COOH, Ammonium - (NH4)+

Question 7

Common weak bases names and formulas (give two)

Answer 7

Ammonia - NH3, Sodium carbonate - Na2CO3 (any metal carbonate or hydrogencarbonate)

Question 8

How to identify a Conjugate acid

Answer 8

A conjugate acid is the same as the starting base plus H+.

Question 9

How to identify a Conjugate base

Answer 9

A conjugate base is the same as the starting acid minus H+.

Question 10

Products of reaction between acid and metal

Answer 10

salt and hydrogen

Question 11

Products of acid and metal carbonate or metal hydrogencarbonate

Answer 11

salt, carbon dioxide and water

Question 12

Products of acid and metal hydroxide or metal oxide

Answer 12

salt and water

Question 13

Strong acid definition and common examples

Answer 13

Strong acids ionise completely when dissolved in water. Examples include HCl, HBr, HI, HNO3 and H2SO4

Question 14

weak acids definition and common examples

Answer 14

Weak acids ionise incompletely when dissolved in water. Examples include carboxylic acids (eg HCOOH and CH3COOH),
HF, HCN, HNO2, H2SO3

Question 15

Calculation to find pH from H+ concentration

Answer 15

pH = – log [H+]

Question 16

Calculation to find [H+] from pH

Answer 16

[H+] = 10^-pH

Question 17

pH scale range for acids and bases

Answer 17

Each one-unit change in the pH scale corresponds to a ten-fold change in H+ concentration.
<7 acidic, 7 neutral, >7 basic/alkaline

Question 18

Definition of a neutralisation reaction

Answer 18

An reaction between an acid and a base (ie a proton transfer) that produces an ionic salt and water as products.

Question 19

Polyprotic Acids

Answer 19

Species that donates multiple protons, H+, during ionisation

Question 20

Amphiprotic Species

Answer 20

Amphiprotic species can either donate or accept a proton, H+.

Question 21

Monoprotic (include an example)

Answer 21

Species that donates one proton, H+, during ionisation
Example: HCl, HNO3 or NH4+

Question 22

Diprotic (include an example)

Answer 22

Species that donates two protons, H+, during ionisation
Example: H2SO4 or H2CO3

Question 23

Triprotic (include an example)

Answer 23

Species that donates three protons, H+, during ionisation
Example: H3PO4

Question 24

Acidic Oxides

Answer 24

Acidic oxides reacting with water producing acids.
When an acidic oxide is dissolved in water, it will decrease the pH of the water sample due to the formation of H+ions. Some common examples for acidic oxides are CO2, NO2 and SO2.