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प्रश्न
Define exothermic and endothermic changes. Give two example in each case.
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
Define exothermic reactions. Give two examples of each.
Why energy is involved in a chemical change?
Name a nitrate which produces oxygen as the only gas.
Name a compound which produces carbon dioxide on heating.
Complete the statement by filling in the blank with the correct word:
The element molybdenum used in the reaction of nitrogen with hydrogen at elevated temperatures is an example of a ________.
Give an example with a balanced equation, of the following reaction:
exothermic reaction
Give an example with a balanced equation, of the following reaction:
photochemical reaction
Differentiate between the following:
Electrolytic decomposition and photochemical decomposition.
Write an Explanation.
Endothermic reaction
Identify the type of chemical reaction given below:
\[\ce{2KClO3 -> 2KCl + 3O2 ^}\]
