Question of Exercise 2

Atom and Molecule of Class 9

Question
A molecule of hydrogen is represented as -

Answer

Option 1 H

Option 2 2H

Option 3 H2

Option 4 All of these

Frequently Asked Questions

What is the chemical formula of ferrous sulphate

Solution:

Solution:

Explanation:

The chemical formula of ferrous sulphate is FeSO4.

The cationic part is ferrous i.e Fe+2 while the anionic part is sulphate i.e SO42-.

Since the charge on both species is equal and opposite i.e 2 , so they balance each other in the compound. 

Final Answer:

Hence, the correct chemical formula of ferrous sulphate is FeSO4.. 

 

Isotonic solutions are solutions having the same

A: Surface tension

B: Vapour pressure

C: Osmotic pressure

D: Viscosity

Solution:

Correct option is: (C) osmotic  pressure.

Explanation:-

Isotonic solutions have the same osmotic pressure because they have the same solute concentration. 

Osmotic pressure depends only on solute concentration and temperature. 

Name the method you will use to separate two immiscible liquids

Solution:

Explanation:

  • Separation of immiscible liquids can be done by a separating funnel.
  • The two liquids are put into the funnel and left for some time. 
  • After some time that settles out and forms two different layers. 
  • The cork of the funnel is opened to allow the bottom liquid to flow.
  • The bottom liquid is collected in another vessel.

Final Answer: Hence Separation of immiscible liquids can be done by a separating funnel.

 

 

 

 

 

What is the chemical formula of Aluminium hydroxide

A. Al (OH)2

B. Al (OH)3

C. Al2 (OH)3

D. Al2 (OH)

Solution:

Explanation:-

The atomic number of Aluminium is 13 and its electronic configuration is [Ne]3s23p1.

 It contain three electron in its valence shell so in a neutral state it can expand it covalency upto 3 So the formula becomes Al (OH)3

Two immiscible liquids are separated by

A: Separating funnel

B: Fractional distillation

C: Chromatography

D: Sublimation

 

Solution:

Correct Option is: (A)

Separating funnel

 

Explanation:

  • Immiscible liquids are those which don't dissolve into each other
  • They can be separated by using a separating funnel.
  • Fractional distillation is used to separate two miscible liquids which have significant differences in their boiling point.
  • Chromatography  is a laboratory method used for the separation of a mixture into its components.
  • Sublimation Is  conversion of a substance from the solid to the gaseous state without becoming liquid.

 

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