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प्रश्न
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
Write a word equation for the chemical change, if any.
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उत्तर
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संबंधित प्रश्न
Write true or false .
A black residue is formed when sugar is heated .
State what you would observe when the following substance is heated in a glass test tube red lead.
Match the pairs.
| a. | Photosynthesis | i. | Tendency to lose electrons |
| b. | Water | ii. | Reactant in combustion process |
| c. | Sodium chloride | iii. | Chemical change |
| d. | Dissolution of salt in water | iv. | Covalent bond |
| e. | Carbon | v. | Ionic bond |
| f. | Fluorine | vi. | Physical change |
| g. | Magnesium | vii. | Tendency to form anion |
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Name the following:
The type of change physical or chemical involved – ‘during respiration in human beings’.
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 dilute hydrochloric acid to silver nitrate.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A coloured substance which leaves on strong heating a black residue and evolves two colourless gases one of which is acidic and the other neutral.
Silver metal can displace hydrogen gas from nitric acid.
Beating an egg to make a cake is a ______.
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
