Chemical Reactions and Equations — Science STD 10 — Question

Which property of plaster of Paris is utilised in making casts for broken limbs in hospitals?

State whether an aqueous solution of washing soda is acidic or alkaline? Give reason for your answer.

Explain why, some materials are biodegradable but some are non-biodegradable.

Name two human body organs where magnetism produced is significant.

Name an indicator which is pink in alkaline solution but turns colourless in acidic solution.

How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?

Veins and arteries carry blood. Which of these carry blood:

1. Away from the heart?
2. Back to the heart?

In what ways can a motor be made more powerful?

Select the mis-matched pair in the following and correct it.

a.	Biomagnification	Accumulation of chemicals at the successive trophic levels of a food chain.
b.	Ecosystem	Biotic components of environment.
c.	Aquarium	A man-made ecosystem.
d.	Parasites	Organisms which obtain food from other living organisms.