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प्रश्न
Write true or false :
No new substance is formed during a chemical reaction.
विकल्प
True
False
उत्तर
False
APPEARS IN
संबंधित प्रश्न
How do the following help in bringing about a chemical change?
catalyst .
Give reason .
A person suffering from acidity is advised to take an antacid.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Reduction is a chemical reaction in which there is
- removal of hydrogen
- removal of oxygen
- addition of oxygen
- none of these
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
FILL IN THE BLANK
........... electrolytes dissociate completely in aqueous state and allow large amount of electricity to flow through it.
TRUE \ FALSE
Ammonia is a good oxidizing agent.
TRUE \ FALSE
Electrolytic refining is a method in which a thin coating of a metal is done over another metal.
Explain the type of reactions on the basis of the direction of reaction.
Fill in the blank
A new substance is always formed in a _______ change.
Explain the following reaction with one suitable example of Combination reactions .
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 a reaction where the following are involved
Heat
What do you observe? When
Barium chloride is added to sodium sulphate solution
Name: Two carbonates do not produce carbon dioxide on heating.
State the original colour of the following substance and colour of residue obtained after heating.
Ammonium dichromate
Distinguish by dilute sulphuric acid.
Copper and magnesium?
Give a word equation for the following reaction.
Two gases which combine to give a solid.
Give a word equation for the following reaction.
A compound which on heating shows – colour change from brown to yellow.
Complete the table given below.
| Heat on sodium chloride | Colour imparted to flame during flame test |
A chemical reaction is often accompanied by external indications or characteristics.
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 __________.
The chemical change is ______.
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
Rusting of Iron: undesirable change:: Dead plants turn into manure: ______.
The percentage composition of Nitrogen in Ureas is ______.
Write the chemical reaction of baking soda with lemon.
Why is spoiling food a chemical change?
______ is the chemical name of rust.
Define the following term:
Chemical change
