Question

1. Which of the following has the highest conductivity

   		Pure Water
   		0.1 M Ba(OH)2 solution
   		0.5 M Ba(OH)2 solution
   		Air

2. Which conductivity point is the equivalence point of the reaction?

   H₂SO₄ +Ba(OH)₂ à BaSO₄   + 2 H₂O

   		The lowest conductivity point
   		The highest conductivity point
   		The start point
   		None of above

Answer 1

1. Conductivity is directly related to number of ions in solution. Pure water is an insulator.

0.1M Ba(OH)2 will have less ions than 0.5M Ba(OH)2 , thus conductivity of 0.5M Ba(OH)2 will be highest.

Option (c) is the correct answer .

2. Precipitation titration;

H2SO4(aq) + Ba(OH)2(aq) >>>> BaSO4(s) + 2H2O(l)

As the titration begins , the conductivity will decrease due to formation of BaSO4 solid . Conductivity will be minimum at equivalence point where all BaSO4 will formed .

After equivalence point, conductivity will rise sharply again.

Thus option (b) lowest conductivity point is the equivalence point of this titration.