Advertisements
Advertisements
प्रश्न
What is a redox reaction? Explain with an example.
Advertisements
उत्तर
A redox reaction is a reaction in which oxidation and reduction reactions take place simultaneously.
When copper oxide is heated with hydrogen, then copper metal and water are formed:
In this reaction, CuO is changing into Cu. That is, oxygen is being removed from copper oxide. Oxygen is being added to hydrogen; H2 is changing into H2O. This shows that oxidation and reduction occur together.
APPEARS IN
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?
What does one mean by exothermic reaction? Give example.
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Give one example of a decomposition reaction which is carried out by applying heat.
What type of chemical reaction takes place when silver bromide is exposed to sunlight?
What type of reaction is represented by the following equation?
\[\ce{NH4NO2 -> N2 + 2H2O}\]
What is meant by a decomposition reaction?
State the change in colour observed in the following case, mentioning the reason:
Silver chloride is exposed to sunlight.
Which of the following can be decomposed by the action of light?
Identify the type of following reaction :
Differentiate between direct combination reaction and a decomposition reaction.
Give a balanced equation for –
A white precipitate obtained during a double decomposition reaction involving a silver salt with sodium salt.
Give a balanced equation for the following type of reaction:
A thermal decomposition reaction in which a metallic nitrate decomposes to give – a basic oxide.
Give a balanced equation for the following type of reaction:
A thermal decomposition reaction in which a compound decomposes to give two new compounds.
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?
Balance the following chemical equation and identify the type of chemical reaction.
`"HgO"("s") overset("(heat)")(->) "Hg"("l") + "O"_2("g")`
Write the molecular formula of calcium carbonate.
