Thursday, June 11, 2015

acid or base , is it confusing ?

acid or base , is it confusing ?

I will write today about acid , so bases well be handled simultaneously . In school we learn only one type of acidity ,although we don't know its name , no one had told us about bronsted or lewis acidity , so i will show them a little ans answer the confusing question " why NH3  is abase" meanwhile .
Firstly we have to remember an important rule of thumb “ don’t store acids in metal tanks unless u re able to overcome hydrogen , that will be evolved “
Now , we all know that acid : is asubstance when dissolved in water give H3O+ “ hydronium ion “ , and base : is a substance when dissolved in water give OH- ion, this is called Arrhenius theory .
Broncted-lowry theory :
It handles with protons , acid : donate proton , base : accept proton
Eg : HNO3 + H2O                  H3O+   + NO3-

      Acid         base                    acid        base

So , until now we can notice two things :
1)     OH- is an example of a base
2)     Acid-base reactions are not restricted to aqueous solutions


Lewis theory :
We always hear this word while studying catalysts and it define acid as : electron-pair acceptor , base : as electron-pair donor .
Ex