MEDIUM

9th CBSE

IMPORTANT

Earn 100

A student tested the solubility of different substances in water at different temperatures and collected the data as given below.

Substance dissolved
Temperature in K

283 293 313 333 353

Solubility

1. Potassium nitrate 21 32 62 106 167

2. Sodium chloride 36 36 36 37 37

3. Potassium chloride 35 35 40 46 54

4. Ammonium chloride 24 37 41 55 66

The solubility values in the table are given as grams of substance dissolved in 100 grams of water to form a saturated solution. Now answer the following question:

Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?

Important Questions on Is Matter Around Us Pure? (Elements, Compounds and Mixtures)

MEDIUM

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions as per the Guidelines of CBSE>Q 1

A student tested the solubility of different substances in water at different temperatures and collected the data as given below.

Substance dissolved	Temperature in K 283 293 313 333 353 Solubility
1. Potassium nitrate	21	32	62	106	167
2. Sodium chloride	36	36	36	37	37
3. Potassium chloride	35	35	40	46	54
4. Ammonium chloride	24	37	41	55	66

The solubility values in the table are given as grams of substance dissolved in 100 grams of water to form a saturated solution. Now answer the following question:

What is the effect of change of temperature on the solubility of a salt?

HARD

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions as per the Guidelines of CBSE>Q 2

Describe the steps to separate each component from a mixture containing iron filings, sulphur, sodium chloride and sand.

HARD

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions as per the Guidelines of CBSE>Q 3

Define a colloid and write its other names. Give an example of each one of:
(a) sol
(b) emulsion
(c) gel
(d) aerosol

HARD

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions on Higher Order Thinking Skills (HOTS)>Q 1

The boiling points of argon, nitrogen and oxygen are

- 180^{0} C, - 196^{0} C

and

- 183^{0} C

respectively. Which of these gases will distill first from their mixture in the air? Justify your answer.

HARD

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions on Higher Order Thinking Skills (HOTS)>Q 2

On adding dil.

HCl

to a mixture of iron filings and sulphur an odorless gas is produced, but a gas with rotten eggs is produced when the same acid is added to iron sulphide. Explain this difference by chemical equations.

EASY

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions on Higher Order Thinking Skills (HOTS)>Q 3

Oxygen is an element with non-metallic nature. What is its molecular formula?

HARD

9th CBSE

IMPORTANT

Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions on Higher Order Thinking Skills (HOTS)>Q 4

Name the method of separation of small pieces of metal in engine oil.

MEDIUM

9th CBSE