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Question
Define chemical reaction.
Solution
Chemical reaction : Any chemical change in matter which involves its transformation into one or more new substances is called a chemical reaction.
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MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Compounds, which in their molten state allow an electric current to pass through them are called
- electrolytes
- non-electrolytes
- non-conductors
- none of these
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True or false
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NaOH + HCl → NaCl + H2O
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Electrochemical reaction
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Complete and balance the following reaction:
Pb(NO3)2 + KI →
Complete the following table and write your observations.
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Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
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Shake the gas with red litmus solution |
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Shake the gas with blue litmus solution |
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Apply a burning splint to a gas |
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HCl and Cl2
Distinguish by heating the following in dry test tubs.
Zinc carbonate, Copper carbonate and lead carbonate.
Distinguish by heating the following in dry test tubs.
Zinc nitrate and copper nitrate.
Select the correct answer for the following options:
The basic gas obtained when two gases react in presence of a catalyst and the reaction is exothermic.
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- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Thermal decomposition of mercury [II] oxide.
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc nitrate to nitrogen dioxide
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 |
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