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प्रश्न
Differentiate between direct combination reaction and a decomposition reaction.
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उत्तर
Direct combination: “Is a reaction in which two elements or compound combine to give one new compound.”
\[\ce{C + O2->CO2}\]
Decomposition reaction: “A chemical compound (breaks up) decomposes into two or more simpler substances.”
\[\ce{Copper carbonate->Copper oxide + Carbon dioxide}\]
\[\ce{CuCO3->CuO + CO2}\]
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संबंधित प्रश्न
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
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.
(a) What is substance P? Write its common name as well as chemical formula.
(b) What is substance Q?
(c) What is gas R?
(d) What is substance S? What is its clear solution known as?
(e) What is substance T? Name any two natural forms in which substance T occurs in nature.
The white solid compound A decomposes quite rapidly on heating in the presence of a black substance X to form a solid compound B and a gas C. When an aqueous solution of compound B is reacted with silver nitrate solution, then a white precipitate of silver chloride is obtained along with potassium nitrate solution. Gas C does not burn itself but helps burn other things.
(a) What is compound A?
(b) What is compound B?
(c) What is gas C?
(d) What do you think is the black substance X? What is its function?
(e) What is the general name of substances like X?
State an important use of decomposition reactions.
Give one example of a decomposition reaction which is carried out with electricity.
Name the product formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?
A student wants to study a decomposition reaction by taking ferrous sulphate crystals. Write two precautions he must observe while performing the experiment.
Photolysis is a decomposition reaction caused by ______
On heating blue coloured powder of copper (II) nitrate, in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed
- Write a balanced chemical equation of the reaction.
- Identify the brown gas X evolved.
- Identify the type of reaction.
- What could be the pH range of aqueous solution of the gas X?
Write the molecular formula of calcium carbonate.
