Answer the following Questions :-
1. How does an acid taste?
2. Is calcium hydroxide an acid or base?
3. What is Neutralisation? Give an example.
4. List the properties of caustic soda.
5. Differentiate between acidic oxides and basic oxides with examples.
6. Is KOH an alkali? How can you say that without experimentally testing your result?
7. Write balanced equations for the reactions of (a) Zinc with Hydrochloric acid (b) Magnesium with Sulphuric acid.
8. Give two differences between an Acid and a Base.
9. What is an Indicator? Give two examples alongwith their action.
10. State three general properties of acids.
Answers
Required Answers:-
1. An acid is sour in taste.
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2. A calcium hydroxide is a base which is also known as Slaked lime.
Calcium hydroxide has the formula Ca(OH)₂. It is formed when CaO (Calcium Oxide) reacts with water (H₂O).
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3. Neutralisation is a reaction in which acids and bases react with each other to neutralize themselves. The products of this reaction are mainly salt and water.
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4. Uses of Caustic Soda (or Sodium Hydroxide, NaOH):-
- NaOH is used to manufacture soap, detergents, etc.
- It is used for degreasing metals.
- NaOH is used ti purify bauxite.
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5. Differences between acidic oxide and basic oxide are as follows:-
Acidic Oxides:-
- Acidic oxides dissociate in water to give acid.
- Non-metals react with oxygen to give out metallic oxide.
Basic Oxides:-
- Basic oxides dissociate in water to form bases (commonly known as alkali).
- Metals react with oxygen to produce basic oxides.
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6. Yes, KOH (Potassium Hydroxide) is a base. It is because it contains hydroxide ion or OH⁻ ion. We know, hydroxide ion is only present in the case of bases.
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7. (a) Zn + 2HCl → ZnCl₂ + H₂
(b) Mg + H₂SO₄ → MgSO₄ + H₂
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8. Differences between acids and bases:-
Acids:-
- Acids when dissociated in water produce H⁺ ion.
- Acids turn blue litmus red.
Bases:-
- Bases when dissociated jn water produce OH⁻ ion.
- Bases turn red litmus blue.
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9. An indicator helps us to determine whether a substance is acidic, basic or neutral in nature.
Eg:-
(i) Litmus paper:-
- Acid - Blue litmus red
- Base - Red litmus blue
(ii) Methyl Orange Solution:-
- Acid - Orange color becomes red
- Base - Orange color becomes yellow.
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10. Three general properties of acids are:-
- Acids are generally sour in taste.
- According to Arrhenius concept of acids, acids dissociate in water to produce H⁺ (or hydrogen) ion.
- Acids turn blue litmus red, methyl orange solution red, phenolphthalein solution colourless.
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Required Answers:-
1. An acid is sour in taste.
________________________________
2. A calcium hydroxide is a base which is also known as Slaked lime.
Calcium hydroxide has the formula Ca(OH)₂. It is formed when CaO (Calcium Oxide) reacts with water (H₂O).
________________________________
3. Neutralisation is a reaction in which acids and bases react with each other to neutralize themselves. The products of this reaction are mainly salt and water.
________________________________
4. Uses of Caustic Soda (or Sodium Hydroxide, NaOH):-
NaOH is used to manufacture soap, detergents, etc.
It is used for degreasing metals.
NaOH is used ti purify bauxite.
________________________________
5. Differences between acidic oxide and basic oxide are as follows:-
Acidic Oxides:-
Acidic oxides dissociate in water to give acid.
Non-metals react with oxygen to give out metallic oxide.
Basic Oxides:-
Basic oxides dissociate in water to form bases (commonly known as alkali).
Metals react with oxygen to produce basic oxides.
________________________________
6. Yes, KOH (Potassium Hydroxide) is a base. It is because it contains hydroxide ion or OH⁻ ion. We know, hydroxide ion is only present in the case of bases.
________________________________
7. (a) Zn + 2HCl → ZnCl₂ + H₂
(b) Mg + H₂SO₄ → MgSO₄ + H₂
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8. Differences between acids and bases:-
Acids:-
Acids when dissociated in water produce H⁺ ion.
Acids turn blue litmus red.
Bases:-
Bases when dissociated jn water produce OH⁻ ion.
Bases turn red litmus blue.
________________________________
9. An indicator helps us to determine whether a substance is acidic, basic or neutral in nature.
Eg:-
(i) Litmus paper:-
Acid - Blue litmus red
Base - Red litmus blue
(ii) Methyl Orange Solution:-
Acid - Orange color becomes red
Base - Orange color becomes yellow.
________________________________
10. Three general properties of acids are:-
Acids are generally sour in taste.
According to Arrhenius concept of acids, acids dissociate in water to produce H⁺ (or hydrogen) ion.
Acids turn blue litmus red, methyl orange solution red, phenolphthalein solution colourless.
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