Acids, Bases and Salts

Question 1

How to check for the presence of acid?

Answer 1

1. Use indicators such as litmus paper, Universal Indicator and pH meter
2. Reaction with metals, carbonates and alkalis or based

Question 2

How to check for the presence of hydrogen?

Answer 2

Use a lighted splint. The lighted splint extinguishes a ‘pop’ sound of hydrogen is present

Question 3

How to check for the presence of carbon dioxide?

Answer 3

Use limewater. White precipitate will be formed in limewater of carbon dioxide is present

Question 4

What does the strength of an acid/alkali depend on?

Answer 4

Depends on the extent of its ionisation in water

Question 5

Why is an acid/alkali a strong acid/alkali?

Answer 5

The acid/alkali ionises fully in water to produces hydrogen ions

Question 6

Why is an acid/alkali a weak acid/alkali?

Answer 6

The acid/alkali ionises partially in water to produce hydrogen ions

Question 7

How to check for the presence of ammonia?

Answer 7

Use moist red litmus paper. The moist red litmus paper will turn blue if ammonia is present

Question 8

pH 0-1 description?

Answer 8

Concentration of H+: Very high
Concentration of OH-: Very low
Nature of solution: Strong acid

Question 9

pH 2-6 description?

Answer 9

Concentration of H+: Moderate high
Concentration of OH-: Moderate low
Nature of solution: Weak acid

Question 10

pH 7 description?

Answer 10

Concentration of H+: Equal
Concentration of OH-: Equal
Nature of solution: Neutral

Question 11

pH 8-12 description?

Answer 11

Concentration of H+: Moderate low
Concentration of OH-: Moderate high
Nature of solution: Weak alkali

Question 12

pH 13-14 description?

Answer 12

Concentration of H+: Very low
Concentration of OH-: Very high
Nature of solution: Strong alkali

Question 13

What are the types of oxides?

Answer 13

1. Basic Oxide
2. Amphoteric Oxide
3. Acidic Oxide
4. Neutral Oxide

Question 14

Basic Oxides

Answer 14

Metals combine with oxygen 
(except lead, aluminium and zinc)
Copper(ii) oxide, CuO
Sodium oxide, Na2O
Magnesium oxide, MgO
Reacts with acids to form salt and water

Question 15

Amphoteric Oxides

Answer 15

Metals combine with oxygen
Lead(ii) oxide, PbO
Aluminium oxide, Al2O3
Zinc oxide, ZnO
Reacts with either acids or based to form salt and water

Question 16

Acidic Oxides

Answer 16

Non-metals combine with oxygen
Carbon dioxide, CO2
Sulfur dioxide, SO2
Phosphoric trioxide, P2O3
Reacts with bases to form salt and water

Question 17

Neutral Oxides

Answer 17

Non-metals combine with oxygen
Carbon monoxide, CO
Water, H2O
No reaction with acids and bases