CHEM-111                                         QUIZ-3                                   Oct 13, 2004

ID #                                                                

 

Q.1      Define each of the following ?

            i) Arrhenius acid

 

            ii) Bronsted-Lowry acid

 

Q.2      Which of the following value, a stronger conjugate base has

a)         Ka <1               b) Ka > 1                      c) Ka = 1

 

Q.3      Weak acids are :

            a) Partially dissociate with low ka value,  b) Fully dissociate  with low Ka value ,             c) Partially dissociate with high ka value  d) Fully dissociate with high Ka value

 

Q.4      Write down the balance equation of the following acids and base in water.

            a) HClO4(aq)  +   H2O(aq)

 

            b) CH3COOH(aq)  +   H2O(aq)

 

Q.5.     Identified the acid(a), base(b) , the conjugate base(cb) and  the conjugate acid(ca) of the following reactions.

            a) H2SO4(aq)                +           H2O(aq)                     H3O+ (aq)          +     HSO4(aq)

            b) HOCl(aq)                 +           C6H5NH2(aq)             OCl(aq)             +     C6H5NH3+

            c) H2O(aq)                    +            HONH3(aq)              HONH2 (aq)      +      H3O+ (aq)

 Q.6     Give the order from strongest to weakest strength, of the following chemicals.

                        H2O,   Ka = 1.0 x 10-14;  HOCl,   Ka  =  3.5 x 10 -8;    HNO3  ,  Ka  >> 1

                        NH4 + Ka  =  5.6 x 10-10

 

 

Q.7      In this reaction

            HSO4- (aq)         +        OH- (aq)                   SO42-        +    H2O(l)  

            What are conjugate acid - base pairs:

 

Q.8      What is concentration of  H+ in a 2.5 M HCl solution

            a)  0 M             b)  1.25 M                   c) 2.5 M                       d) 5.0 M

 

Q.9      Calculate the pH and [OH]  of  5 x 10-3 M of HClO4 solution

 

 

 

 

Q.10    Calculate the [H+]  and [OH-] for solution, Identify each solution is acidic, neutral or basic. If; a) pH  = -1.0      

 

            b) pOH   = 5.0