1) Which of the following chemicals has affected the ozone layer?
a) Carbon compound b)
c) Chlorofluoro carbon d) Carbon tetra chloride]
2) Which of the following substance is used in the hydrogenation of vegetable oil?
a) Finely divided nickel b) Platinised gauze
c)Finely divided platinum d) Finely divided iron
3) Digestion in human body is an example of which type of reaction?
a) Displacement reaction b) Decomposition reaction
c) Double decomposition reaction d) Combination reactions
4) In the experiment, a burning matchstick is held near the mouth of the test tube containing hot HgO. It burns brightly. Why?
a) Mercury oxide decomposes into mercury and hydrogen
b) No change in the compound takes place
c) Heat is available from the flame
d) Oxygen gas is evolved
5) Which of the following statement is true for sodium atoms and sodium ions?
a) They are chemically same b) They have same number of protons
c) They have identical number of electrons d) They form covalent bonds
6) When an ionic bond is formed?
a) The combining atoms gain electrons
b) The combining atoms lose electrons
c) A metallic element reacts with nonmetallic element
d) Two metallic elements reacts
7) Which is the electronic configuration of chlorine atom?
a) 2,8,7 b) 2,8,8 c) 2,8,5 d) 2,8,4
8) What is the percentage of sulphur in a molecule of sulphuric acid?
a) 40 b) 35 c) 65 d) 32.65