Elements And Metals : 2

Question 21 :

In fireworks, the green flame is produced because of

A). sodium
B). barium
C). mercury
D). potassium
Answer : Option B

Question 22 :

Permanent hardness of water can be removed by adding

A). chlorine
B). washing soda
C). potassium permanganate
D). bleaching powder
Answer : Option B

Question 23 :

Marsh gas is

A). nitrogen
B). ethane
C). methane
D). hydrogen
Answer : Option C

Question 24 :

LPG consists of mainly

A). methane, ethane and hexane
B). ethane, hexane and nonane
C). methane, hexane and nonane
D). methane, butane and propane
Answer : Option D

Question 25 :

Air is a/an

A). compound
B). element
C). electrolyte
D). mixture
Answer : Option D