Unit - 4.1 Importance of water and its resources — CHEMISTRY STD 6 — Question

From the following substances given below state which will form a solution in the same.
(a) sodium carbonate
(b) calcium carbonate
(c) charcoal powder
(d) sodium sulphate
(e) table salt
(f) powdered particles of lead from a lead pencil
(g) iron powder
(h) copper filings
(i) sand particles
(j) honey

How does chemistry help in medical applications? Explain properly.

By giving one example for each, define:Homogeneous mixture

Name three dissolved impurities.

Give word equation for the following conversion:
Carbon dioxide in the air to carbohydrates in plants.

Briefly describe how respiration takes place in human beings.

Identify the pure substances and mixture from the following list :Solid common salt
Milk
Air
Oxygen
fruit juice
brass
copper sulphate crystals
distilled water
sugar solution
honey
ice cream
iron sulphate

Ice on absorption of heat converts to ‘X’ a process called ____ [vaporization / melting]. ‘X’ changes to water vapour on ____ [heating / cooling]. Water vapour changes back to ‘X’ on ____ [freezing / condensation]. The constant temperature at which ice changes into ‘X’ is called its ____ [fusion point / melting point / boiling point].

Identify (a) homogeneous mixture and (b) heterogeneous mixture from the following list.
common salt solution
a mixture of salt and Sulphur
milk
brass
air
fruit juice
cooked vegetables of peas and onions