Advertisements
Advertisements
प्रश्न
When electric current is passed through acidulated water ______ of water takes place.
पर्याय
Oxidation
Displacement
Electrolysis
Reduction
zinc
copper
Double displacement
Decomposition
उत्तर
When electric current is passed through acidulated Decomposition of water takes place.
Explanation:
Electrolysis take place, divide water in the ratio 2 :1 hydrogen and oxygen and the reaction is a decomposition reaction. It is decomposition reaction because when electricity is passed through the water a single compound split into two elements hydrogen and oxygen so it is called decomposition reaction.
APPEARS IN
संबंधित प्रश्न
Give reason.
Wasp sting is treated with vinegar.
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
TRUE \ FALSE
Evaporation of water is a physical change. True or false ?
Give an example of a reaction where the following are involved
Electricity
Give an example of the following chemical change.
Two solids combine to form a liquid
Define:
Photochemical reaction
Give one example
Complete the following table and write your observations.
Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
|
Shake the gas with red litmus solution |
||||
Shake the gas with blue litmus solution |
||||
Apply a burning splint to a gas |
Write your observation and a balanced equation in the case of the following substances being heated.
Copper nitrate.
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.
Complete the table given below.
Heat on iodine crystals | Colour of vapours evolved |
Complete the table given below.
Flame test for calcium chloride | Acid used for flame test |
Give a balanced equation for the conversion of an ammonium salt to a basic gas.
Circle the odd one out. Give reason for your choice
What is the role of a catalyst in a chemical reaction?
Discuss how acid rain occurs due to emission of smoke from vehicles and industries?
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
Classify each of the following, as a physical or a chemical change. Give reasons.
(a) Drying of a shirt in the sun.
(b) Rising of hot air over a radiator.
(c) Burning of kerosene in a lantern.
(d) Change the colour of black tea by adding lemon juice to it.
(e) Churning of milk cream to get butter.
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.
What changes do you expect?
Iron and rust are the same substances.
Write the chemical reaction of baking soda with lemon.