1) pH of 0.005 M of H2SO4 is : - A ) 2 , B ) 6 , C ) 7 ,

1 ) pH of 0.005 M of H2SO4 is : -

A ) 2 ,                                                              B ) 6 ,

C ) 7 ,                                                             D ) None of these ,

Correct Answer : -   A ) 2 ,

Solution : -

H2SO4 is strong acid .

H2SO4   ---------->  2H⁺  +  1SO^-₄  .

H2SO4  =  0.005 M ,

So ,  2H⁺  =  2 ( 0.005 ) = 0.01 M .

pH  =  - log [ H⁺ ]  =  - log [ 0.01 ] = - log [ 10^(-2) ] ,

pH  =  2 ( 1 )  =  2 , Answer .

 

2 ) Volume of CH4 (methane) is 100 cm3  and  volume of H2 ?

CH4 + H2O  -------->  3H2 + CO .

A ) 100 cm3  ,                                                           B ) 300 cm3  ,

C ) 438 cm3  ,                                                           D ) None of these ,

Correct Answer : -   B ) 300 cm3  ,

Solution : -

1 dm3 = 1000 cm3 .

So , volume of CH4 ( methane )  =  100 cm3  =  0.1 dm3 .

So moles of methane =  volume / dm3  =  0.1 / 22.4  M .

So , as by given reaction in question : -

1 M  of  CH4  gives  3 M  of  H2 .

So ,  ( 0.1 / 22.4 ) M  of  CH4  gives  3( 0.1 / 22.4 ) M  of  H2 .

So , volume of H2  =  moles x STP .

Volume of H2  =  3( 0.1 / 22.4 )  x  22.4  ,

Volume of H2  =  0.3  dm3  =  300 cm3  ,  Answer .

 

3 ) Oxidation number of sulpher in sulphuric acid ( H2SO4 )  : -

A ) + 3 ,                                                                      B ) – 4 ,

C ) + 6 ,                                                                      D ) None of these ,

Correct Answer : -   C ) + 6 ,

 

4 ) Oxidation number of  N in NH₃is : -

A ) - 3 ,                                                                       B ) – 4 ,

C ) + 6 ,                                                                      D ) None of these ,

Correct Answer : -   A ) - 3 ,

 

5 ) Proton : -

Charge : -  Protons have  + 1  charge . 

Ionization energy : -  Proton is already charged , so cannot break more .

Radius : -  Proton has very small radius .

Hydration energy : -  Proton is easily dissolved or attracted by water , so hydration energy is very large .

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