Advertisements
Advertisements
प्रश्न
Differentiate between the following:
Thermal decomposition and thermal dissociation.
Advertisements
उत्तर
Thermal decomposition and thermal dissociation.
Decomposition of a compound on heating into two elements or element and compound or into two new compounds. It is an irreversible reaction.
Thermal dissociation is the decomposition of a substance into two or more simpler substances on heating but the reaction is reversible.
\[\ce{NH4Cl⇌[Heat][Cool]NH3 + HCl}\]
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?
Rewrite the following statements by selecting the correct options:
\[\ce{CaCO3 ->[\Delta] CaO + CO2 ^}\] is a __________ reaction.
What type of chemical reaction takes place when limestone is heated?
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.
A student wants to study a decomposition reaction by taking ferrous sulphate crystals. Write two precautions he must observe while performing the experiment.
Photolysis is a decomposition reaction caused by ______
Marble statues are corroded or stained rain water. Identify the main reason.
Balance the following chemical equation and identify the type of chemical reaction.
`"H"_2"O"_2("l") overset("U V")(->) "H"_2"O"("l") + "O"_2("g")`
When lead nitrate is heated strongly in a boiling tube, two gases are liberated and a solid residue is left behind in the test tube.
- Name the type of chemical reaction and define it.
- Write the name and formula of the coloured gas liberated.
- Write the balanced chemical equation for the reaction.
- Name the residue left in the test tube and state the method of testing its nature (acidic/basic).
