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प्रश्न
How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased?
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उत्तर
\[\ce{\underset{peroxide}{\underset{Hydrogen}{2H2O}_{2(l)}} -> \underset{water}{2H2O} + \underset{oxygen}{O2\uparrow}}\]
- The decomposition of hydrogen peroxide (H2O2) into water and oxygen takes place slowly at room temperature.
- However, hydrogen peroxide decomposes rapidly in the presence of manganese dioxide (MnO2) powder, which acts as a catalyst.
- Thus, by adding manganese dioxide (MnO2) powder, the rate of a chemical reaction can be increased.
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संबंधित प्रश्न
Why is the amount of gas collected in one of the test tubes in the following Activity double of the amount collected in the other? Name this gas.
- Take a plastic mug. Drill two holes at its base and fit rubber stoppers in these holes. Insert carbon electrodes in these rubber stoppers as shown in the following Fig.
- Connect these electrodes to a 6 volt battery.
- Fill the mug with water such that the electrodes are immersed. Add a few drops of dilute sulphuric acid to the water.
- Take two test tubes filled with water and invert them over the two carbon electrodes.
- Switch on the current and leave the apparatus undisturbed for some time.
- You will observe the formation of bubbles at both the electrodes. These bubbles displace water in the test tubes.
- Is the volume of the gas collected the same in both the test tubes?
• Once the test tubes are filled with the respective gases, remove them carefully. - Test these gases one by one by bringing a burning candle close to the mouth of the test tubes.
Caution: This step must be performed carefully by the teacher.
- What happens in each case?
- Which gas is present in each test tube?
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
What type of reaction is represented by the digestion of food in our body?
State an important use of decomposition reactions.
What type of chemical reaction is used to extract metals from their naturally occurring compounds like oxides or chlorides?
What type of reaction is represented by the following equation?
2 FeSO4 → Fe2 O3 + SO2 + SO3
What type of reaction is represented by the following equation?
NH4 CI → NH3 + HCI
What type of chemical reaction is represented by the following equation?
X → Y + Z
What is a decomposition reaction?
Which of the following can be decomposed by the action of light?
(a) NaCl
(b) KCl
(c) AgCl
(d) CuCl
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
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 are thermal decomposition reactions ? Explain with an example.
What does one mean by endothermic reaction? Give example.
Give a scientific reason.
When the gas formed on heating limestone is passed through freshly prepared lime water, the lime water turns milky.
(a) Design an activity to demonstrate the decomposition reaction of lead nitrate.
(b) Draw labelled diagram of the experimental set-up. List two main observations.
(c) Write balanced chemical equation for the reaction stating the physical state of the reactant and the products.
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.
Differentiate between direct combination reaction and a decomposition 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 the following type of reaction:
A thermal decomposition reaction in which a compound decomposes to give two new compounds.
Differentiate between the following:
Electrolytic decomposition and photochemical decomposition.
What is electrolysis?
Photolysis is a decomposition reaction caused by ______
Which one of the following processes involves chemical reactions?
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.
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.
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.
- 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.
What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.
Write the molecular formula of calcium carbonate.
Write one equation for decomposition reactions where energy is supplied in the form of light.
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.
