Advertisements
Advertisements
प्रश्न
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
उत्तर
Silver nitrate solution is kept in a laboratory in coloured reagent bottles because if kept in a colourless bottle, it will react with sunlight, causing oxidation and decomposition to silver oxide.
APPEARS IN
संबंधित प्रश्न
FILL IN THE BLANK
A .............. change is a temporary change.
TRUE \ FALSE
Electrolytic refining is a method in which a thin coating of a metal is done over another metal.
Define electrolysis.
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)
An ______ is drawn in between the reactants and products while writing the equation for a chemical reaction.
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 |
State the conditions necessary for a chemical change or reaction.
Define Photochemical reaction
Give an example
Write the chemical reaction where the following changes are observed.
Gas is evolved
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Define:
Photochemical reaction
Give one example
What do you observe when HCI is passed through a silver nitrate solution.
Rusting of Iron: undesirable change:: Dead plants turn into manure: ______.
______ change results in the change of the substance.
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide.
(a) Is this a physical or a chemical change?
(b) Can you prepare one acidic and one basic solution by using the products formed in the above process? If so, write the chemical equation involved.
Rusting of iron is ______.
Write the equation for the process of formation of rust.
Chemical changes are important in our day-to-day life. Give examples.
______ is a chemical substance is used in whitewashing.
