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प्रश्न
Rewrite the following statements by selecting the correct options:
\[\ce{CaCO3 ->[\Delta] CaO + CO2 ^}\] is a __________ reaction.
विकल्प
combination
displacement
double displacement
decomposition
उत्तर
Decomposition
In decomposition reactions, one compound breaks down (or decomposes) to form two or more products. When calcium carbonate is heated, it forms calcium oxide and releases carbon dioxide.
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संबंधित प्रश्न
Write one equation for decomposition reactions where energy is supplied in the form of heat.
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.
State an important use of decomposition reactions.
Give one example of a decomposition reaction which is carried out with electricity.
What type of chemical reaction is used to extract metals from their naturally occurring compounds like oxides or chlorides?
What type of chemical reaction take place when electricity is passed through water?
What type of reaction is represented by the following equation?
NH4NO2 → N2 + 2H2O
Name the product formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?
When a green iron salt is heated strongly, its colour finally changes to brown and odour of burning sulphur is given out.
(a) Name the iron salt.
(b) Name the type of reaction that takes place during the heating of iron salt.
(c) Write a chemical equation for the reaction involved.
Two metals X and Y form the salts XSO4 and Y2SO4, respectively. The solution of salt XSO4 is blue in colour whereas that of Y2SO4 is colourless. When barium chloride solution is added to XSO4 solution, then a white precipitate Z is formed alongwith a salt which turns the solution green. And when barium chloride solution is added to Y2SO4 solution, then the same white precipitate Z is formed alongwith colourless common salt solution.
(a) What could the metals X and Y be?
(b) Write the name and formula of salt XSO4.
(c) Write the name and formula of salt Y2SO4.
(d) What is the name and formula of white precipitate Z?
(e) Write the name and formula of the salt which turns the solution green in the first case.
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.
(a) What do you think metal M is?
(b) What could be gas X2?
(c) Name the metal salt MX.
(d) Name any two salt solutions which on mixing together can produce a precipitate of salt MX.
(e) What type of chemical reaction takes place when salt MX is exposed to light? Write the equation of the reaction?
Explain the following type of chemical reaction, giving two examples for it:
Decomposition reaction
How will you obtain Nitrogen dioxide from lead nitrate.
Also give balanced equations for the reactions
What do you mean by redox reaction ? Explain with the help of an example.
Classify the following reaction into different type:
\[\ce{2KClO3(s)->[\Delta] 2KCl(aq) + 3O2(g)}\]
Give a balanced equation for –
An electrolytic decomposition reaction involving a neutral liquid
Differentiate between the following:
Electrolytic decomposition and photochemical decomposition.
Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is:
Give the ratio in which hydrogen and oxygen are present in water by volume.
When SO2 gas is passed through a saturated solution of H2S, which of the following reaction occurs?
Assertion: Decomposition of vegetable matter into compost is an endothermic reaction.
Reason: Decomposition reaction involves breakdown of a single reactant into simpler products.
Balance the following chemical equation and identify the type of chemical reaction.
`"HgO"("s") overset("(heat)")(->) "Hg"("l") + "O"_2("g")`
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?
These consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
Assertion: Silver bromide decomposition is used in black and white photography.
Reason: Light provides energy for this exothermic reaction.
A metal nitrate 'A' on heating gives a metal oxide along with evolution of a brown coloured gas 'B' and a colourless gas, which helps in burning. Aqueous solution of 'A' when reacted with potassium iodide forms a yellow precipitate.
- Identify 'A' and 'B'
- Name the types of the reactions involved in the above statement.
What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.
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).
Write the molecular formula of calcium carbonate.
A solution of a substance ‘X’ is used for whitewashing.
- Name the substance ‘X’ and write its formula.
- Write the reaction of the substance ‘X’ named in the above formula with water.
