QUIZ  # 4, Chapter -15

ID #                                         Name:                                                              Date:

 

Attempt all questions.

 

[3]

Q.1      a)   Calculate the pH of 0.100 M propionic acid (HC3H5 O2 )

and % dissociation of the acid.          Ka = 1.3 x 10-5          

 

 

 

 

 

 

 

 

 

                       

 

 

            b)   The common ions will drive the equilibrium towards ……………..

            and decrease the dissociation of ………………

[3]

Q.2.     Calculate the pH a mixture containing 0.100 M of HONH2  and 0.100 M of      HONH3Cl (weak acid)                         Kb = 1.1 x 10-8.

 

 

 

 

 

 

 

 

[4]

Q. 3.    a) Calculate the pH of buffer solution after addition of 0.02 mol of HCl to                                   1.00 L of  a solution of 5.00 M HC2H3O2, and 5.00 M of NaC2H3O2.

                 Ka = 1.8 x 10-5

 

 

 

 

 

 

 

 

                  b)  A buffer solution is made by dissolving NH4Cl and NH3 in H2O . Write equation to show how this buffer neutralized added H+ and OH- .