Conditions:
- Heating;
- Presence of an oxidizing agent; in this case it is manganese (IV) oxide.
Procedure:
- Hydrochloric acid is reacted with manganese (IV) oxide (dropwise)
Explanation:
- Manganese (IV) oxide oxidizes hydrochloric acid by removing hydrogen resulting into chlorine.
- The manganese (IV) oxide is reduced to water and manganese chloride.
- The resultant chlorine gas is passed through a bottle containing water.
Reason:
- To remove hydrogen chloride fumes (gas) which is very soluble in water.
- Next it is passed through concentrated sulphuric acid or anhydrous calcium chloride; to dry the gas.
Collection:
(a). Wet chlorine is collected over brine (saturated sodium chloride solution) or hot water.
Reason:
- It does not dissolve in brine and is less soluble in water
(b). Dry chlorine is collected by downward delivery (upward displacement of air)
Reason:
- It is denser than air (2.5 times).
Note:
- Chlorine may also be dried by adding calcium chloride to the jar of chlorine.
(c). The first bottle must contain water and the second concentrated sulphuric acid.
Reason:
- If the gas is first passed through concentrated sulphuric acid in the first bottle then to the water; it will be made wet again.
Kavungya answered the question on
April 29, 2019 at 09:40