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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.
\[\ce{\underset{\text{(lead nitrate)}}{2Pb(NO3)2}->[heat]\underset{\text{lead monoxide}}{2PbO} +\underset{\text{nitrogen dioxide}}{4NO2} + O2}\]
APPEARS IN
संबंधित प्रश्न
MATCH THE COLUMNS
| 1 . `H_2` + `CI_2` `→` 2HCI | a. displacement reaction |
| 2. `2FeCI_3`+ `H_2` `→` `2FeCI_2` +2HCI` | b. addition of an electronegative redical |
| 3. Fe + `CuSO_4` `→``FeSO_4` +Cu` | c. removal of an electronegative redical |
| 4. `2H_2O` +`4NO_2`+`O_2` `→` `4HNO_3` | d.reduction by adding hydrogen |
| 5. 3Fe +`3CI_2` `→` `2FeCI_3` | e.electrolysis of water |
| 6. `FeCI_3`+ 3NaOH `→``Fe(OH)_3``↓`+NaCI | F.double decomposition,precipitation reaction |
| 7.`2H_2O` `→` `2H_2``↑`+`O_2` | e. combination or synthesis reaction |
TRUE \ FALSE
Temperature at which a liquid starts boiling is known as the boiling point of that liquid. True or false ?
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\[\ce{CuCO3 ->[\Delta]}\]
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| Flame test for calcium chloride | Acid used for flame test |
True or False. If false, give the correct answer.
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- Digestion of food.
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2Mg + O2 → 2Mg O
Give an example where heat, light, and sound are produced during a chemical change.
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______ is the chemical name of rust.
