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प्रश्न
Give a reason.
Wasp sting is treated with vinegar.
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उत्तर
Wasp stings are alkaline and they can be neutralized by vinegar which is a weak acid.
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संबंधित प्रश्न
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
Chlorine (Cl2) molecule is formed by ______ of electrons between two chlorine atoms.
Give an example of the following chemical change.
Two gases combine to form white solid
Give an example of the following chemical change.
Two solids combine to form a liquid
Write the chemical reaction where the following changes are observed.
Precipitate is formed
Name affects the acidified K2Cr2O7 paper and also turns lime water dirty milky.
Name: Two carbonates do not produce carbon dioxide on heating.
Name: A brown gas
A chemical reaction is often accompanied by external indications or characteristics which include –
- 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 – Addition of water to quicklime.
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc carbonate to zinc oxide
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 |
Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.
Complete the statement by filling in the blank with the correct word:
The reddish-brown precipitate obtained during a double decomposition precipitation reaction between an iron salt and alkali is __________.
Higher order Thinking question
Peeled and unpeeled banana does not look the same. Does that mean peeling banana is a chemical change?
Limestone contains ______ mainly.
What is the role of a catalyst in a chemical reaction?
Photosynthesis is a chemical charge. Justify your answer.
Both CO2 and H2 gases are ______.
Acid rain is a result of ______.
