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प्रश्न
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Why are decomposition reactions called the opposite of combination reactions? Explain with equations of these reactions.
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उत्तर
Decomposition reactions occur when a compound breaks up into two or more simpler substances. On the other hand, combination reactions occur when two or more substances combine to form a single substance. Thus, decomposition reactions are the opposite of combination reactions.
Decomposition Reactions:
\[\ce{CaCO3_{(s)} -> CaO_{(s)} + CO2_{(g)}}\]
\[\ce{2H2O_{(l)} ->[Electricity] 2H2_{(g)} + O2_{(g)}}\]
Combination Reactions:
\[\ce{2H2_{(g)} + O2_{(g)} -> 2H2O_{(l)}}\]
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
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संबंधित प्रश्न
Write one equation for decomposition reactions where energy is supplied in the form of heat.
What type of reaction is represented by the digestion of food in our body?
State an important use of decomposition reactions.
Give one example of a decomposition reaction which is carried out by applying heat.
What type of chemical reaction is used to extract metals from their naturally occurring compounds like oxides or chlorides?
What is meant by a decomposition reaction?
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
What does one mean by endothermic reaction? Give example.
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.
A student wants to study a decomposition reaction by taking ferrous sulphate crystals. Write two precautions he must observe while performing the experiment.
Differentiate between the following:
Thermal decomposition and thermal dissociation.
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?
Which one of the following processes involves chemical reactions?
Which of the following is an endothermic process?
The reaction of calcium carbonate, with freshly prepared lime water, is shown below:
Answer the questions with the help of a diagram:
- What type of reaction does calcium carbonate undergoes?
- What change in colour is observed in lime?
- Write the chemical equation.
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.
