Answer:
i) Upwards delivery
ii) Downwards delivery
Step-by-step explanation:
The methods used in the collection of gases are quite different depending on the state of the gas. The solubility and density of gases are the factors that determine the method of collection to be used.
Upwards delivery is used to collect gases that are soluble in water and lighter compared to air. Examples of these kind of gases include; Cl2 and SO2
Downwards delivery is used to collect gases that are soluble in water and denser than air. An example of this kind of gas is ammonia gas, NH4.