Select the correct answer from A, B, C, D & E for each statement given below:

A: Gunpowder

B: Iodine

C: Boron

D: Helium

E: Bromine

1. A diatomic molecule

2. A metalloid

3. A non-metal which is lustrous

4. A mixture consisting of elements & a compound

5. A noble gas

The diagram represents fractional distillation for separation of mixtures. Answer the following:

1. Can two immiscible liquids be separated by this process.

2. Separation of liquids by this process is based on which physical property.

3. If methyl alcohol & water are to be separated, which liquid would remain in flask 'X' after condensation.

4. Give a reason for the above answer.

5. State the purpose of the fractionating column in the apparatus.

Select the correct answer from the choice in bracket to complete each sentence

1. Dust in air is an example of …………… [heterogeneous/homogeneous] mixture.

2. A soluble solid is separated from an insoluble solid by …………… [fractional crystallisation / solvent extraction].

3. The reactive element from the two monoatomic elements is …………… [neon/silicon].

4. Compounds are …………… [homogeneous or heterogeneous/ always homogeneous] in nature.

5. An example of a monoatomic molecule is …………… [hydrogen/helium].

Give reasons for the following statements:

1. Components in a mixture can be separated by physical methods only.

2. Centrifugation can be used for separating an insoluble heavier solid, present in an insoluble solid-liquid mixture.

3. The filter paper made into a cone & placed in a funnel for filtering out the solid particles in a solid-liquid mixture, should be moistened before placing.

4. Brass & bronze are examples of mixtures, while copper sulphate & lead nitrate are examples of compound.

5. Zinc is considered an element, while zinc sulphide is considered a compound.