CBSE Class 10 Science Sample Paper 2013 Set 05

1] A non‐metal X exists in two different forms Y and Z. Y is the hardest natural substance,whereas Z is a good conductor of electricity. Identify Y and Z.

2] What is the minimum resistance which can be made using five resistors each of 1/5 ?

3] When is lactic acid formed in our muscles?

4] What is Plaster of Paris? How it is obtained from Gypsum. Write chemical reaction. Give its one use.

5] A solution of potassium chloride when mixed with silver nitrate solution, an insoluble white substance is formed. Write the chemical reaction involved and also mention the type of the chemical reaction?

6] Two green plants are kept separately in oxygen free containers, one in the dark and the other in continuous light. Which one will live longer? Give reasons

7] Give the events that occur during photosynthesis.

8] Describe the steps involved in reflex action.

9] Write chemical equations for the reactions taking place when

      (i) zinc sulphide is heated in air

      (ii) calcination of zinc carbonate is done

      (iii) when manganese dioxide is heated with aluminium powder

10] (a) Why do we store silver chloride in dark coloured bottles? 

     (b) How does slaked lime is prepared from calcium oxide.

11] Write the balanced chemical equations for the following reactions:

     (a) Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogen carbonate.

     (b) Sodium hydrogen carbonate on reaction with hydrochloric acid gives sodium chloride and liberates carbon dioxide.

12] A student prepared solutions of (i) an acid and (ii) a base in two separate beakers. She forgot to label the solutions and litmus paper is not available in the laboratory. Since both the solutions are colourless, how will she distinguish between the two?

13] What happens at the synapse between two neurons?

Please refer to attached file for CBSE Class 10 Science Sample Paper 2013 Set E