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प्रश्न
How do the following help in bringing about a chemical change?
heat.
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उत्तर
Some chemical reactions take place only in the presence of heat.
e.g. When lead nitrate is heated, it breaks into lead monoxide, nitrogen dioxide and oxygen.
\[\ce{\underset{\text{(lead nitrate)}}{2Pb(NO3)2}->[heat]\underset{\text{lead monoxide}}{2PbO} +\underset{\text{nitrogen dioxide}}{4NO2} + O2}\]
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संबंधित प्रश्न
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TRUE \ FALSE
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| b. | Water | ii. | Reactant in combustion process |
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| d. | Dissolution of salt in water | iv. | Covalent bond |
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| f. | Fluorine | vi. | Physical change |
| g. | Magnesium | vii. | Tendency to form anion |
Give an example of a reaction where the following are involved
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\[\ce{Pb(NO3)2 ->[\Delta]}\]
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Lead nitrate
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium dichromate.
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Give balanced equation for the following conversion affected by heat alone on the substance:
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Match the chemical reactions in List I with the appropriate answer in List II.
| List I | List II | ||
| 1. | \[\ce{XY⇌[heat]X + Y}\] | A: | Displacement reaction |
| 2. | \[\ce{XY->X + Y}\] | B: | Double decomposition |
| 3. | \[\ce{X+Y- + A+B^-->X+B- + A+Y-}\] | C: | Endothermic reaction |
| 4. | \[\ce{X + YZ->XZ + Y}\] | D: | Thermal dissociation |
| 5. | \[\ce{X + Y->[heat]XY -\Delta}\] | E: | Decomposition reaction |
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
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