English Medium Class 9 - CBSE Question Bank Solutions

Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order

1. Rutherford’s atomic model
2. Thomson’s atomic model
3. Bohr’s atomic model

Write any two observations which support the fact that atoms are divisible.

The feature that is not a characteristic of protochordata?

Chemical nature of chitin is ______.

Which of the following are physical changes?

(i) Melting of iron metal

(ii) Rusting of iron

(iii) Bending of an iron rod

(iv) Drawing a wire of iron metal

Suggest separation technique(s) one would need to employ to separate the following mixture.

Mercury and water

Suggest separation technique(s) one would need to employ to separate the following mixture.

Potassium chloride and ammonium chloride

Suggest separation technique(s) one would need to employ to separate the following mixture.

Common salt, water and sand

Suggest separation technique(s) one would need to employ to separate the following mixture.

Kerosene oil, water and salt

The ‘sea-water’ can be classified as a homogeneous as well as a heterogeneous mixture. Comment.

While diluting a solution of salt in water, a student by mistake added acetone (boiling point 56°C). What technique can be employed to get back the acetone? Justify your choice.

What would you observe when

a saturated solution of potassium chloride prepared at 60°C is allowed to cool to room temperature.

What would you observe when

an aqueous sugar solution is heated to dryness.

What would you observe when

a mixture of iron filings and sulphur powder is heated strongly

Name the process associated with the following

Settling of sand when a mixture of sand and water is left undisturbed for some time.

You are given two samples of water labelled as ‘A’ and ‘B’. Sample ‘A’ boils at 100°C and sample ‘B’ boils at 102°C. Which sample of the water will not freeze at 0°C? Comment.

Give an example of each mixture having the following characteristics. Suggest a suitable method to separate the components of this mixture

Two volatile components with appreciable differences in boiling points.

A colloid is a ______ mixture and its components can be separated by the technique known as ______.

A mixture of chloroform and water are taken in a separating funnel is mixed and left undisturbed for some time. The upper layer in the separating funnel will be of ______ and the lower layer will be that of ______.

A mixture of two or more miscible liquids, for which the difference in the boiling points is less than 25 K can be separated by the process called ______.