Question 5
(a)
Differentiate between the following:
Hard water and Soft water
fii) Efflorescence and Deliquescence
für Exothermic reaction and Endothermic reaction
(b)
Give an equation for the formation of ozone in the atmosphere.
(ii) What is the function of ozone layer in the atmosphere?
Answers
Explanation:
(1) hard water is acidic and soft water is basic
(2) o2+o - o3
ozone
Answer
(a)
(I) Hard water... is water that contains an appreciable quantity of dissolved minerals (like calcium and magnesium).
Soft water... is treated water in which the only ion is sodium.
(ii)Efflorescence means spontaneous loss of water by a hydrated salt when the aqueous vapour pressure of the hydrate is greater than the partial pressure of the water vapour in the air.
Deliquescence is the process by which a substance absorbs moisture from the atmosphere and dissolves in it to make a solution
(iii)The difference between endothermic and exothermic reactions lies in the words themselves. "Thermic" refers to heat, just as in the word "thermometer." "Exo" means "outside" and "endo" means "inside." Thus, an endothermic reaction pulls heat into an object or area, while an exothermic reaction expels heat.
(b)
(I)The chemical formula of ozone is O3. In the earth's stratosphere, ozone is formed from a two-step reactive process. First, sunlight breaks apart an oxygen molecule (O2 you'll recall) into two oxygen atoms. In the second step, these oxygen atoms collide with another oxygen atom to make ozone.
(ii).ozone is a gas in the atmosphere that protects everything living on the Earth from harmful ultraviolet (UV) rays from the Sun. Without the layer of ozone in the atmosphere, it would be very difficult for anything to survive on the surface.