1)25 mL of a saturated solution of phenyl acetic acid requires 17.70 mL of 0.1850 M NaOH for its neutralisation.  What is the pH of saturated solution of phenyl acetic acod .  Assume Ka for the acid = 5.56 x 10^-5 (ans pH = 2.57 )

 

2)Calculate the pH of a solution obtained by mixing 0.1 ltr of a strong acid solution of pH = 4, and o.2 ltr a solution of strong base of pH = 10. ( ans 9.5228)

 

3) calculate the  pH of a solutin made  by mixing 50 mL of 0.2 M NH4Cl and 75 mL of 0.1 M NaOH  Given Kb for NH4 OH = 1.8 x 10 ^-5 (Ans 9.74 )

 

4) Calculate approximate pH of 0.05 M solution of carbonic acid . Given

 

H2 CO3  H +  +HCO3^- :  K1  = 4.3 x 10^-7

 

HCO3^-  H ^+ + CO3^-2  :  K2 = 5.6 x 10 ^-11

 

5) calculate the pH of a solution obtained by mixing 60 mL of 0.45 N  NaOH and 40  mL of 0.3 N HCl . (Ans 13.17 )

 

6) 0.12 mL of a solution of KOH ( 50% by weight of KOH) , specific gravity 1.5 g/cm^3 is diluted to 250 mL .  calculate its pH. (ans 11.80 )

 

7) calculate pH of a solution of benzoic acid in water being soluble upto 2.06 g/dm^3.Ka=6.4x10^-5   ( ans 3 )

 

8) A weak base BOH of concentration 0.02 mol /ltr  has a pH if 10.45 , If 100 mL of this base are mixed with 10 mL of 0.1 M HCl, what will be the pH of mixture. (ans 8.598 ).

 

9) At _{^{25 degree C what changes in pH occur when o.1 millimole of a strong acid is added to 25 mL of :  (a) H2O  (b) 0.025 M HCl  (c) 0.025 M Na OH ?  ( Ans  (a) 4.602  (b) 0.064  (c) 0.076 )}}