Advertisements
Advertisements
प्रश्न
Differentiate between direct combination reaction and a decomposition reaction.
Advertisements
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.”
\[\ce{Copper carbonate->Copper oxide + Carbon dioxide}\]
\[\ce{CuCO3->CuO + CO2}\]
APPEARS IN
संबंधित प्रश्न
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Taking into consideration the relationship in the first pair, complete the second pair
2H2 + O2 → 2H2O :Combination Reaction :: 2HgO → 2Hg + O2:_________
Rewrite the following statements by selecting the correct options:
\[\ce{CaCO3 ->[\Delta] CaO + CO2 ^}\] is a __________ reaction.
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.
Give a balanced equation for –
An electrolytic decomposition reaction involving a neutral liquid
Which among the following statement(s) is (are) true?
Exposure of silver chloride to sunlight for a long duration turns grey due to
(i) the formation of silver by decomposition of silver chloride.
(ii) sublimation of silver chloride.
(iii) decomposition of chlorine gas from silver chloride.
(iv) oxidation of silver chloride.
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.

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.
Write one equation for the decomposition reaction where energy is supplied in the form of light.
