Advertisements
Advertisements
प्रश्न
Define chemical reaction.
Advertisements
उत्तर
Any chemical change in matter that involves its transformation into one or more new substances is called a chemical reaction.
संबंधित प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
Complete and balance the following chemical equations
NaCI + `AgNO_3` `→`
Complete and balance the following chemical equations:
Zn + `"H"_2"SO"_4` `→`
(dil)
TRUE \ FALSE
Copper can displace iron from iron sulphate.
What are homogenous reactions ?
Fill in the blank:
The basic conditions necessary for a chemical reaction is _______
Write true or false .
A black residue is formed when sugar is heated .
State four conditions necessary for a chemical reaction to take place.
Explain by writing a word equation.
Respiration is a chemical change.
Give an example of a reaction where the following are involved
Light
Give reason for the following:
Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
When hydrogen burns in oxygen, water is formed; when electricity is passed through water, hydrogen and oxygen are given out. Name the type of chemical change involved in the two cases.
Complete and balance the following reaction:
Pb(NO3)2 + KI →
Select the correct answer for the following options:
The basic gas obtained when two gases react in presence of a catalyst and the reaction is exothermic.
Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to sodium sulphite.
Arrange the following statements in correct sequence:
- One side is water-loving and other water-hating molecules.
- When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
- The dirt surrounded by the detergent molecules floats in the water making it dirty.
- Finally, the cloth is clean.
- The detergent molecules have two sides.
- Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.
When magnesium is burnt in the air, a new substance is formed which is ______.
Is the conversion of milk into ice cream a chemical change?
Write the effects of chemical reactions.
