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प्रश्न
Fill in the blank
A new substance is always formed in a _______ change.
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उत्तर
A new substance is always formed in a chemical change.
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संबंधित प्रश्न
How would you show that setting of curd is a chemical change?
Complete and balance the following chemical equations:
N2 + O2 →
FILL IN THE BLANK
Negatively charged ions are called ..........
TRUE \ FALSE
Positively charged electrode is called the anode. True or false ?
State four conditions necessary for chemical reactions to take place.
Fill in the blank:
The basic conditions necessary for a chemical reaction is _______
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
The conversion of ferrous sulphate to ferric sulphate is ______ reaction.
Give an example of the following chemical change.
A reaction where colour change is noticed
What do you observe? When
Barium chloride is added to sodium sulphate solution
Name affects the acidified K2Cr2O7 paper and also turns lime water dirty milky.
Distinguish by dilute sulphuric acid.
Sodium sulphide and sodium sulphite?
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper carbonate to copper oxide
Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Calcium hydroxide.
What is the use of indicator?
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.
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
Acid rain is a result of ______.
Write the effects of chemical reactions.
