HARD
9th CBSE
IMPORTANT
Earn 100

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

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

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 -1800C, -1960C and -1830C 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
IMPORTANT
Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions on Higher Order Thinking Skills (HOTS)>Q 5
Write one point of difference between evaporation and sublimation. 
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 6
Solubility of a gas in water decreases on heating. Is the dissolution of gas in water exothermic or endothermic? 
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 7
Solubility of a salt in water at 273 K is lower than that at 300 K. Is the process of solubility exothermic or endothermic? 
MEDIUM
9th CBSE
IMPORTANT
Secondary Chemistry>Chapter 2 - Is Matter Around Us Pure? (Elements, Compounds and Mixtures)>Questions on Higher Order Thinking Skills (HOTS)>Q 8
A system shows Tyndall effect and Brownian motion. Does this system represent a true solution or colloid?