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प्रश्न
What is meant by a decomposition reaction?
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उत्तर
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.
संबंधित प्रश्न
Write the balanced chemical equation for the following and identify the type of reaction.
\[\ce{Zinc carbonate(s) -> Zinc oxide(s) + Carbon dioxide(g)}\]
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.
Taking into consideration the relationship in the first pair, complete the second pair
2H2 + O2 → 2H2O :Combination Reaction :: 2HgO → 2Hg + O2:_________
Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light and electricity
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.
- What is substance P? Write its common name as well as chemical formula.
- What is substance Q?
- What is gas R?
- What is substance S? What is its clear solution known as?
- 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.
- What is compound A?
- What is compound B?
- What is gas C?
- What do you think is the black substance X? What is its function?
- What is the general name of substances like X?
Give one example of a decomposition reaction which is carried out by applying heat.
What type of chemical reaction takes place when electricity is passed through water?
What type of reaction is represented by the following equation?
\[\ce{NH4NO2 -> N2 + 2H2O}\]
Name the product formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?
State the change in colour observed in the following case, mentioning the reason:
Silver chloride is exposed to sunlight.
When a green iron salt is heated strongly, its colour finally changes to brown and odour of burning sulphur is given out.
- Name the iron salt.
- Name the type of reaction that takes place during the heating of iron salt.
- Write a chemical equation for the reaction involved.
A metal salt MX when exposed to light splits up to form metal M and a gas X2. Metal M is used in making ornaments whereas gas X2 is used in making bleaching powder. The salt MX is itself used in black and white photography.
- What do you think metal M is?
- What could be gas X2?
- Name the metal salt MX.
- Name any two salt solutions which on mixing together can produce a precipitate of salt MX.
- What type of chemical reaction takes place when salt MX is exposed to light? Write the equation of the reaction.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Thermal decomposition of a substance is brought about with the help of
- reactants
- water
- wind
- heat
What is a redox reaction? Explain with an example.
What does one mean by endothermic reaction? Give example.
Identify the type of following reaction :
How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased?
Answer the following question.
2 g of silver chloride is taken in a china dish and the china dish is placed in sunlight for some time. What will be your observation in this case? Write the chemical reaction involved in the form of a balanced chemical equation. Identify the type of chemical reaction.
Classify the following reaction into –
- Direct combination
- Decomposition
- Displacement
- Double decomposition
The reaction is – Zinc hydroxide on heating gives zinc oxide and water.
Give a balanced equation for –
A thermal decomposition reaction involving heat on limestone [calcium carbonate]
Give a balanced equation for –
A double decomposition neutralization reaction involving an acid and a base
Complete the statement by filling in the blank with the correct word:
Decomposition of silver salts in the presence of sunlight is an example of _________.
Give a balanced equation for the following type of reaction:
A thermal decomposition reaction in which a compound decomposes to give two new compounds.
Differentiate between the following:
Thermal decomposition and thermal dissociation.
Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is:
Which one of the following processes involves chemical reactions?
Which of the following is an endothermic process?
Marble statues are corroded or stained rain water. Identify the main reason.
Complete the following reaction:
\[\ce{C_12H_22O11->[Heat]}\] ______ + ______.
When lead nitrate is heated strongly in a boiling tube, two gases are liberated and a solid residue is left behind in the test tube.
- Name the type of chemical reaction and define it.
- Write the name and formula of the coloured gas liberated.
- Write the balanced chemical equation for the reaction.
- Name the residue left in the test tube and state the method of testing its nature (acidic/basic).
