CBSE Class 10 Science Question Paper 2007 (3)

CBSE Class 10 Science Question Paper 2007 (3). Students can download the last year question papers using the link below. Free download of examination question papers with solutions. Last 10 year question papers should be practised to get better marks in examinations.

SCIENCE AND TECHNOLOGY (Theory)

SECTION A

1. What is the role of a catalyst in a chemical reaction ? 

2. Which class of compounds gives a positive Fehling’s test ? 

3. Approximately how many stars are there in the Milky Way ? 

4. What is meant by the statement, “Potential difference between points A and B in an electric field is 1 volt.” ? 

5. State the ‘Law of Chemical Equilibrium’. Write an expression for the equilibrium constant (K) for the reaction, 

N₂ (g) + 3H₂(g)→ 2 NH₃ (g) + 92 kJ

6. Name the organic acid present in vinegar. Write a chemical equation which representsa the commercial method for the preparation of this acid from methanol. 

7. Distinguish between ‘artificial’ and ‘natural’ satellites. Why are artificial satellites called “eyes in the sky” ? 

8. An electric lamp is marked 100 W, 220 V. It is used for 5 hours daily. Calculate

(i) its resistance while glowing.

(ii) energy consumed in kWh per day. 

9. (a) Write the chemical name and formula of bleaching powder.

(b) Why does bleaching powder smell of chlorine when exposed to air ?

(c) Write chemical equation to represent the action of dilute hydrochloric acid on bleaching powder. 

Please click the link below to download pdf file of CBSE Class 10 Science Question Paper 2007 (3)