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Q. 4. What is the difference in the molecular formula of any two consecutive members of a homologous series of organic compounds?

Ans. The two consecutive members of a homologous series of organic compounds differ by CH2 (i.e. one carbon and two hydrogen).

Q. 5. Redraw the given diagram and show the path of the refracted ray :

Q. 6. Element M forms a chloride with the formula MCl2 which is a solid with high melting point. To which group of the Periodic Table does the element ‘M’ belong?

Ans. M forms MCl2, a solid with high melting point. This information shows that the valency of M is 2 or M loses two electrons. Therefore M belongs to the group II of the periodic table.

Q. 7. The elements of the third period of the Periodic Table are given below.

(a) Which is more non-metallic, S or Cl?
(b) Which has higher atomic mass, Al or Cl?

Ans. (a) Cl is more non-metallic than S because on moving from left to right in a period, nuclear charge increases so the tendency to gain electrons increases (i.e. non-metallic character).
(b) Cl has higher atomic mass because on moving from left to right in a period, atomic number increases. Simultaneously, atomic mass increases.

Q. 8. Solid calcium oxide was taken in a container and water was added slowly to it.

(i) State the two observations made in the experiment.
(ii) Write the name and chemical formula of the product formed.

Science 2008 Question Papers Class X
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	All Sets (PDF)				Set 1		Set 1
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