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प्रश्न
Define exothermic and endothermic changes. Give two example in each case.
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उत्तर
Exothermic Reaction
The chemical reactions which proceed with the evolution of heat energy are called exothermic reactions.
Examples:
Carbon burns in oxygen to form carbon dioxide and heat energy is produced.
C + O2 → CO2 + Heat
Water added to quick lime (calcium oxide), slaked lime (calcium hydroxide) is produced with a lot of heat energy.
CaO + H2O → Ca(OH)2 + Heat
Endothermic Reaction
The chemical reactions which proceed with the absorption of heat energy are called as endothermic reactions.
Examples:
When nitrogen and oxygen are heated together to a particular temperature of about 3000oC, nitric oxide gas is formed.
N2 + O2 + Heat → 2NO
Calcium carbonate decomposes into carbon dioxide and calcium oxide when heated to a temperature of about 1000oC.
CaCO3 + Heat → CaO + CO2
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संबंधित प्रश्न
State the effect of an exothermic reaction on the surroundings.
What do you observe? When
Lead nitrate is heated.
State which type of chemical reaction proceeds with evolution of heat energy.
Explain the term energy changes in a chemical change or reaction.
Give an example with a balanced equation, of the following reaction:
exothermic reaction
Select the correct answer from the options given below:
State the gaseous product formed, when
Two gases one of them neutral combines by absorption of light energy.
Differentiate between the following:
Electrolytic decomposition and photochemical decomposition.
Assertion: A drop of petrol when touched with finger gives a chill feeling.
Reason: The above phenomenon is an endothermic one.
The Dissolution of glucose in water is also an ______ change.
Give a scientific reason.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
