Experimental Chemistry

Gas syringe

- suitable for ALL gases

- used for measuring volumes of gases

Displacement of water

- suitable for gases that are INSOLUBLE or SLIGHTLY soluble in water

CO2, N2, O2, H2

Downward delivery of gas

- Suitable for gases that are DENSER than air

CO2, SO2, Cl2, O2, HCl

Upward delivery

- for gases LESS DENSE than air

H2, N2, NH3

Concentrated sulfuric acid

- to dry ACIDIC and NEUTRAL

Quicklime (calcium oxide)

- to dry ALKALINE gases and all NEUTRAL gases

Fused calcium chloride

- Can be used for most gases except NH3

Neutral gases

- Hydrogen, H2

- Oxygen O2

- N2

Acidic gases

- Carbon dioxide CO2

- Chlorine gas Cl2

- Hydrogen chloride HCl

- Sulfur dioxide SO2

Alkaline gas

- NH3

Sublimation

- used to separate a substance that changes from the solid to gaseous state directly

- resulting solid deposit is called the sublimate

E.g.

1. Iodine

2. Ammonium chloride

3. Dry ice (Solid carbon dioxide)

4. Mothball (naphthalene)

Crystalisation

- Process of obtaining soluble solid from its solution

- suitable for soluble solids that decomposes on heating

E.g.

> Sugar solution

> hydrated salts