MODEL PAPER 5 — Science STD 10 — Question

State the uses of plane mirrors.

State two positions in which a concave mirror produces a magnified image of a given object. List two differences between the two images.

Catenation is the ability of an atom to form bonds with other atoms of the same element. It is exhibited by both carbon and silicon. Compare the ability of catenation of the two elements. Give reasons.

Friedrich Wohler converted an inorganic compound into an organic compound in the laboratory.

1. Give the name and formula of inorganic compound.
2. Write the name and formula of organic compound formed.

What is meant by 22 carat gold? Name the metals which are usually alloyed with gold to make it harder.

Write any two observations in an activity which may suggest that a chemical reaction has taken place. Give an example in support of your answer.

In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?

Which of the following are endothermic reactions and which are exothermic reactions?

1. Burning of natural gas.
2. Photosynthesis.
3. Electrolysis of water.
4. Respiration.
5. Decomposition of calcium carbonate.

Name some of the solar energy devices.

Why have detergents replaced soap as a washing agent?