1 ) An amount of water of mass 20 g at 0 C ( Celsius ) is mixed with 40 g of water at 10 C . Final temperature of mixture is : - A ) 10 C , B ) 40 C , C ) 273 C , D ) None of these ,

1 ) An amount of water of mass 20 g at 0 C ( Celsius ) is mixed with 40 g of water at 10 C . Final temperature of mixture is : -

A ) 10 C ,                                                                    B ) 40 C ,

C ) 273 C ,                                                                 D ) None of these ,

Correct Answer : -   B ) 40 C ,

Solution : -

 

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2 ) If the molecule of HCL is totally polar , the observed value of dipole moment is 1.03 D but the experimental value of dipole moment was 6.12 D . Calculate the percentage of ionic character ?

A ) 1.3 %  ,                                                                 B ) 17 %  ,

C ) 71 %  ,                                                                  D ) None of these ,

Correct Answer : -   B ) 17 %  ,

Solution : -

Dipole moment is the difference in electronegativity of two atoms of a molecule .

µ = 0 , ( For non – polar )  And  µ ≠ 0 , ( For polar ) .

So ,

Ionic character  =  ( Observed / Calculated ) x 100 ,

Ionic character  =  ( 1.03 D / 6.12 D ) x 100 ,

Ionic character  =  17 %  ,  Answer .

 

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3 ) Calculate the percentage of covalent character of HX having bond length = 1.62 A and observed dipole  moment = 0.39 D ?

A ) 1.3 %  ,                                                                 B ) 17 %  ,

C ) 95 %  ,                                                                  D ) None of these ,

Correct Answer : -   C ) 95 %  ,

Solution : -

 

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