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Question
What is meant by a decomposition reaction?
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Solution
A decomposition reaction is a chemical reaction in which a single compound breaks down to simpler products. It is the opposite of a combination reaction.
When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide:
\[\ce{\underset{(Limestone)}{\underset{Calcium carbonate}{CaCO3_{(s)}}} ->[Heat][(Decomposition)] \underset{(Lime)}{\underset{Calcium oxide}{CaO_{(s)}}} + \underset{Carbon dioxide}{CO2_{(g)}}}\]
RELATED QUESTIONS
What does one mean by exothermic reaction? Give example.
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Write one equation for decomposition reactions where energy is supplied in the form of heat.
Rewrite the following statements by selecting the correct options:
\[\ce{CaCO3 ->[\Delta] CaO + CO2 ^}\] is a __________ reaction.
A solid substance P which is very hard is used in the construction of many buildings, especially flooring. When substance P is heated strongly, it decomposes to form another solid Q and a gas R is given out. Solid Q reacts with water with the release of a lot of heat to form a substance S. When gas R is passed into a clear solution of substance S, then a white precipitate of substance T is formed. The substance T has the same chemical composition as starting substance P.
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MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Thermal decomposition of a substance is brought about with the help of
- reactants
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- wind
- heat
What are thermal decomposition reactions ? Explain with an example.
What is a redox reaction? Explain with an example.
Identify the type of following reaction :
Study the following figure and answer questions.
a) After heating Calcium carbonate, which gas is formed in a test tube?
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c) Write down the chemical reaction showing the product formation after heating the Calcium carbonate.
A student wants to study a decomposition reaction by taking ferrous sulphate crystals. Write two precautions he must observe while performing the experiment.
How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased?
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Give a balanced equation for –
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Write the molecular formula of calcium carbonate.
Write one equation for the decomposition reaction where energy is supplied in the form of light.
