Class 10 Acids, Bases-Salts notes

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REACTION OF ACIDS AND BASES WITH METAL

When an acid reacts with metal, it produces salt and hydrogen gas. This reaction can be shown by following generic equation.

Acid + Metal à Salt + Hydrogen

Activity: To understand the reaction between metal and acid, let us do the following activity.

  • Take 5 mL dilute sulphuric acids in a test tube and put some zinc granules in it.
  • Close the mouth of the test tube with a cork and insert a delivery tube in the cork.
  • Put another end of the delivery tube in a beaker which is filled with soapy water.
  • You will notice that bubbles appear in the test tube. After some time, bubbles also appear in soap water.
  • Bring a burning matchstick near the bubbles over soap water. The matchstick burns with a pop sound. This indicates that evolved gas is hydrogen.

This reaction can be shown by the following equation:

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The reaction of zinc with some other acids can be shown as follows:

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Some other examples of reaction between metal and acid are as follows:

When sodium reacts with sulphuric acid then sodium sulphate and hydrogen gas are formed.

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When potassium reacts with sulphuric acid then potassium sulphate and hydrogen gas are formed.

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When iron reacts with hydrochloric acid then iron chloride and hydrogen gas are formed.

Important Note: The confirmatory test for the evolution of hydrogen gas involves bringing a burning matchstick or burning splinter near the gas. If the matchstick/splinter burns with a pop sound, it indicates the evolution of hydrogen gas.

The reaction of the base with metals: Bases may not react with all metals. However, zinc reacts with sodium hydroxide to give sodium zincate and hydrogen gas. This reaction can be shown by the following equation:

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Reaction Of Acids With Metal Carbonate And Metal Hydrogen Carbonate:

When an acid reacts with metal carbonate or metal hydrogen carbonate, it gives salt, carbon dioxide and water. This reaction can be shown by following generic equations:

Acid + Metal carbonate → Salt + Carbon dioxide + Water

Acid + Metal hydrogen carbonate → Salt + Carbon dioxide + Water

Activity: To understand the reaction between acid and metal carbonate/hydrogen carbonate, let us do the following activity.

  • Take two test tubes and label them as A and B.
  • Take 0.5 g sodium carbonate in test tube A and 0.5 g sodium hydrogen carbonate in test tube B.
  • Add 2 ml dilute hydrochloric acid in both the test tubes.
  • Insert a delivery tube to the test tube;
  • Pass the evolved gas into lime water.
  • You will observe that the lime water turns milky. It indicates the evolution of carbon dioxide.

This reaction can be shown by the following equation:

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When carbon dioxide is passed into lime water, the following reaction takes place.

This is because of formation of calcium carbonate that the lime water turns milky.

Important Note: The confirmatory test for the evolution of carbon dioxide involves passing the gas in lime water. If the lime water turns milky, it shows the evolution of carbon dioxide.

When an excess of carbon dioxide is passed into lime water then calcium hydrogen carbonate is formed. Since calcium hydrogen carbonate is soluble in water hence white colour from limewater disappear.

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Since calcium hydrogen carbonate is soluble in water, hence the white colour of lime water disappears after this reaction.

Some other examples of reaction between metal carbonate/hydrogen carbonate and acid are as follows:

When magnesium carbonate reacts with hydrochloric acid than magnesium chloride, carbon dioxide and water are formed.

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Exam Tips: Whenever reaction happens between metal and carbonate or hydrogen carbonate, it results in the evolution of carbon dioxide gas because carbonate ion contains carbon and oxygen.


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Chemical Reactions and Equations:

Types of Chemical Reaction:

Acids, Bases and Salts:

Common Properties of Acid and Base:

Metals and Non-metals:

Carbon and its Compounds:

Periodic Classification of Elements:

Life processes:

Control and co-ordination in animals and plants:

Reproduction:

Heredity and evolution: 

Conservation of natural resources:

How do Organism Reproduce

Electricity:

Magnetic effects of current:

Sources of energy:

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