Question

B. Fill in the blanks.
1. Substances that take part in a chemical reaction are called
2. A chemical equation can be represented using the
of
the reactants and products.
3. During a chemical reaction, atoms in the molecules of the reactants rearrange themselves to form
and
one or more
4. The evolution of gas is represented by an upwardly-directed
5. A chemical reaction in which heat energy is evolved is called an
6. Hydrogen sulphide gas smells like
7. Chemical reactions take place by the action of light energy are called
reaction.
reactions.
C. Write true or false. Correct the false statements.
1. New substances that are produced as a result of a reaction are called reactants.
2. When acetic acid is added to sodium bicarbonate, brisk effervescence takes place.
3. Copper(II) sulphide is blue in colour.
4. A chemical reaction in which heat is absorbed is called an exothermic reaction.
5. Chemical reactions that need energy in the form of electricity to take place are called
electrochemical reactions.
6. An enzyme is a substance that acts as a catalyst in living organisms.
D. Write word equations for the following reactions. Also identify reactants and products in
each reaction.
1. Adding a small amount of dilute hydrochloric acid to sodium carbonate
2. Burning magnesium in air
3. Adding water to quicklime (calcium oxide)
4. Adding a solution of silver nitrate to a solution of sodium chloride
5. Reacting ammonia gas with hydrogen chloride gas
6. Passing hydrogen gas through molten sulphur​

Answer 1

Answer:

B. 1) Catalyst

2) Reactants and products

3) Bond

4) Arrow

5) Exothermic reaction

6) Rotten eggs

7) Photochemical reaction