Advertisements
Advertisements
Question
Rewrite the following statements by selecting the correct options:
\[\ce{CaCO3 ->[\Delta] CaO + CO2 ^}\] is a __________ reaction.
Options
combination
displacement
double displacement
decomposition
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
Write the balanced chemical equation for the following and identify the type of reaction.
\[\ce{Zinc carbonate(s) -> Zinc oxide(s) + Carbon dioxide(g)}\]
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:_________
What type of reaction is represented by the digestion of food in our body?
State an important use of decomposition reactions.
What type of reaction is represented by the following equation?
\[\ce{2FeSO4 -> Fe2O3 + SO2 + SO3}\]
What type of reaction is represented by the following equation?
\[\ce{NH4Cl -> NH3 + HCl}\]
What type of chemical reaction takes place when limestone is heated?
What type of chemical reaction takes place when silver bromide is exposed to sunlight?
What is the colour of ferrous sulphate crystals? How does this colour change after heating?
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.
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 along with 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 along with colourless common salt solution.
- What could the metals X and Y be?
- Write the name and formula of salt XSO4.
- Write the name and formula of salt Y2SO4.
- What is the name and formula of white precipitate Z?
- Write the name and formula of the salt which turns the solution green in the first case.
Explain the following type of chemical reaction, giving two examples for it:
Decomposition 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
Give a scientific reason.
When the gas formed on heating limestone is passed through freshly prepared lime water, the lime water turns milky.
Study the following figure and answer questions.

a) After heating Calcium carbonate, which gas is formed in a test tube?
b) When we pass this gas through limewater what change, did you observe?
c) Write down the chemical reaction showing the product formation after heating the Calcium carbonate.
Differentiate between direct combination reaction and a decomposition reaction.
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 _________.
The chemical reaction in which two or more products are formed from a single reactant is called ______ reaction.
What is electrolysis?
Explain the reaction given in the figure.

The following reaction is used for the preparation of oxygen gas in the laboratory:
\[\ce{2KClO3_{(s)} ->[Heat] 2KCl + 3O2_{(g)}}\]
Which of the following statement about the reaction is correct?
Marble statues are corroded or stained rain water. Identify the main reason.

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?

- Identify the gasses evolved at the anode and cathode in the above experimental set up.
- Name the process that occurs. Why is it called so?
- Illustrate the reaction of the process with the help of a chemical equation.
Complete the following reaction:
\[\ce{C_12H_22O11->[Heat]}\] ______ + ______.
What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.
Write one equation for the decomposition reaction where energy is supplied in the form of light.
Write one equation for the decomposition reaction where energy is supplied in the form of electricity.
