HARD
7th CBSE
IMPORTANT
Earn 100

Define acidity of a base. Give one example each of monoacidic, diacidic and triacidic bases.

Important Questions on PREP TEST

HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 28
Two iron nails, one half immersed in distilled water and the other half immersed in saline water, are taken. Which is expected to rust faster?
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 30

Give reason for the following:

A shiny copper vessel turns green after some time.

HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 30

Give reason for the following:

Iron pipes used in homes to carry water are galvanised.

HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 31
Most physical changes are reversible. Explain with two examples.
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 32
Blue litmus paper is dipped in aerated soft drink. What will happen? What is the nature of the solution? 
 
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 33
Explain the term 'displacement reaction' and give an example. 
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 34
Explain why an antacid tablet is taken when you suffer from acidity.
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 3 - PREP TEST>SECTION - B>Q 35
Why do cut vegetables and fruits turn brown when exposed to air?