Q1. Encircle the correct...

Q1. Encircle the correct answer.                                                             /15

1. The conservation of mass is obtained when the total mass of reactants is equal to total mass of

a.products

b.molecules

c.protons

2.At room temperature iron and sulphur

a.do no react

b.react

c.vigorously react

3.The change which is not accompanied by formation of new substance is called a

a.physical change

b.chemical change

c.complex change

4.Natural gas is made up of compound

a.carbon

b.methane

c.ethene

5.If baking soda or fruit salt is mixed with vinegar, there takes place a

a.chemical reaction

b.physical reaction

c.transference

6.Chalk, limestone, marble, eggshells and seashells are made of

1. calcium hydroxide
2. calcium oxide
3. calcium carbonate

7.Burning of fossils fuel results in the production of

1. bio gas
2. oxygen
3. carbon dioxide

8.If two or more substances are combined to form a new substance, the chemical reaction is termed as

1. thermal decomposition
2. combination
3. addition

9.Zinc salt reacts with dilute sulphuric acid to form zinc salt and

1. hydrogen
2. oxygen
3. carbon dioxide

10. Chemical changes are

1. reversible
2. irreversible
3. interchangeable

11.The number of protons in a 'carbon' atom is

1. 6
2. 11
3. 12

12.Compounds which are needed in very small amount but their deficiency lead to scurvy and rickets are

1. vitamins
2. proteins
3. carbohydrates

13.The enzyme which is present in mouth is called

1. salivary enzyme
2. amylase
3. proteases

14. Biuret solution is used to test for

1. vitamins
2. proteins
3. carbohydrates

15. Cellulose compound which cannot be broken down our bodies is called as

1. fiber
2. vitamins
3. carbohydrates