classification of elements, chemical bonding, periodicity in properties & physical transformation - Category wise Question and Answer Practice Test with Solutions

Question : 21

Mendeleev classified elements in

a) eight periods and eight groups

b) seven periods and eight groups

c) increasing order of atomic groups

d) eight periods and seven groups

Question : 22 [IAS (Pre) 2002]

Which of the following statement is not true?

a) Addition of solute to a solution increases its water potential

b) Water vapour pressure of any solution is lower than vapour pressure of pure water

c) Boiling point of any water solution is higher than pure water

d) When a solution is separated with the help of semipermeable membrane, then water flow can be stopped by giving pressure to the solution

Question : 23

Newlands could classify elements only upto

a) chlorine

b) calcium

c) copper

d) chromium

Question : 24 [NDA]

The octet rule is not valid for which one of the following molecules?

a) H₂S

b) NH₃

c) CO₂

d) BF₃

Question : 25 [IAS (Pre) 2005]

Give thought to following statements.

1. In the process of osmosis, the solvent moves towards a dilute solution from the concentrated solution.
2. In reverse osmosis internal pressure but upon a dilute solution.

a) Only 2

b) Both 1 and 2

c) Only 1

d) Neither 1 nor 2