Question

how to seperate a mixture of (sulphur and sand) (CuO and ZnO) (cream from milk) (iron fillings and sugar) (kerosene oil and water)

Answer 1

For the Sulphur and sand mixture, heating them will cause the sulphur to sublimate leaving behind sand while the sulphur fumes could be collected using a funnel with a plug.

For Cuo and Zno,

Copper oxide is metallic oxide. Metallic oxides are basic and can react with acids. Zinc oxide is an amphoteric oxide. Amphoteric oxide can react with acids as well as base. In order to separate copper oxide from zinc oxide, add sodium hydroxide solution to the mixture. Zinc oxide being amphoteric will react with NaOH whereas copper oxide will remain undissolved. Zinc oxide can be recovered from the solution adding acid to it.

Cream and Milk can be separated through centrifugation because milk is denser than cream.

A magnet can be used to separate Iron filings from Sugar.

Kerosene and water can be separated by using a separating funnel.

Answer 2

1.Cuo and Zno separated by calcination and roasting done respectively to get pure metal
2.iron filling and sugar by magnetic process which attract magnetic and separate them
3.A separator is a centrifugal device that separates milk into cream and skimmed milk. 
4.Separating funnel is used to separate the mixture of two immiscible liquids. Kerosene oil and water do not mix with each other and form two separate layers.
5.Sulphur dissolves in carbon disulphide whereas sugar remains undissolved. Hence, a mixture of sulphur and sugar can be separated using carbon disulphide as solvent.