Question 1

1.How is the rate of reaction influenced by
a) raising the temperature of reactants?
b) Adding to the reacting mixture a product of reaction without change in   volume?

Question 2

2.How are the molecules of aldehydes and ketones structurally different? 

Question 3

3.Name one non-metal and one metal which are in liquid state at room temperature.

Question 4

4.Name two other planets of the Solar System which are similar to the Earth in composition and structure.

Question 5

5.How is the strength of the magnetic field at a point near a wire related to the strength of the electric current flowing in the wire?

Question 6

6.How is chloride of lime chemically different from calcium chloride? Why does chloride of lime gradually lose its chlorine when kept exposed to air?

Question 7

7.What is formalin? How does it react with Tollen’s reagent? State any one of its uses. (Out of syllabus)

                                                           OR

Complete the following reaction equations:
(i) CH₃CH₂OH+Na -->
                H
                 |
(ii) H—-C=O+HCN-->(Out of syllabus)

Question 8

8.What is a galaxy? Name two common shapes of galaxies. Why is our

galaxy called Milky Way?(out of syllabus)

Question 9

9.State one point of difference between a natural satellite and an artificial satellite. Name the type of orbit suitable for a geostationary satellite.

Question 10

10.Give one example of a nuclear fusion reaction. Describe one method for making such reactions possible.

Question 11

11.State Arrhenius’ concept of acids and bases. Giving reason, select a strong acid and a weak base from amongst the following substances:

Question 12

12.How is it that we can use detergents for washing clothes even when the water is hard, but not soaps?

What change has been made in the composition of detergents to make them biodegradable?

Question 13

13.Give reasons for the following:
a) Siliconcounts among metalloids.
b) Carbon is not used for making aluminum from aluminum oxide.
c) For making hydrogen by reaction with hydrochloric acid, granulated zinc is preferred to a block of zinc.

Question 14

14.Write chemical equations for reactions taking place when:
a) Zinc carbonate is calcined.
b) Ammonia gas is passed over heated copper (II) oxide.(Out of syllabus)
c)    gas and  gas are together bubbled through water.(Out of syllabus)

Question 15

15.What are electrolytes? Define Faraday’s constant for electrolytic reactions. Find chemical equivalents of Cu (II) (at. wt. 63.5 and Ag(I) (at. wt. 108).

Question 16

16.A 5 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 30 cm. Find the (i) position, (ii) nature and (iii) size of the image formed.

Question 17

17. a) What is meant by ‘critical angle’ for a ray of light going from one medium into another?

b) What is the consequence of making angle of incidence of light, at an interface, greater than the critical angle?

c) Why does a cut diamond shine more than a glass piece with diamond cut?

Question 18

18.Why is it that iron does not occur as a metal in the crust of the earth? What are the common compound forms in which iron occurs? Which of these is more often used for extracting iron? Why are carbon and limestone mixed with the iron ore before feeding it into the blast furnace? Write the chemical equations for the reduction step and the slag formation step.

(Out of syllabus)

                                                        OR

 Define an alloy and an amalgam. State the main constituents of the   following alloys. In what property is each of them different from its main constituent:
(I) Stainless steel (II) Bronze?

Question 19

19.With the help of a labeled ray diagram, show the formation of image of an object by a compound microscope.
A compound microscope has an objective of focal length 0.5 cm and an eye-piece of focal length 2.5 cm. If its tube length is 25 cm, calculate what will be the magnifying power of the microscope.

Question 20

20.On what principle does a solar water heater operate? Draw a labeled schematic diagram for a solar water heater.
The solar constant at a place is 1.4 kW/m². How much solar energy will be received at this place per second over an area of 5m².

OR

What is the main basic cause for winds to blow? Name a part of India where wind energy is commercially harnessed. Compare wind power and power of water flow in respect of generating mechanical and electrical energies. What is the hindrance in developing them?