Question

The resistance of a conductivity cell when filled with 0.05 m solution of an electrolyte x is 100 ohms at 40oc. The same conductivity cell filled with 0.01 m solution of electrolyte y has a resistance of 50 ohms. The conductivity of 0.05 m solution of electrolyte x is1.0x 10-4 s cm-1.Calculate

Answer 1

Answer:

Resistance of a conductivity cell with electrolyte X = 100 ohms

Concentration of an electrolyte X = 0.05 M solution

Resistance of a conductivity cell with electrolyte Y = 50 ohms

Concentration of an electrolyte Y = 0.01 M solution

Conductivity of 0.05 M solution of electrolyte X = 1.0x 10-4S cm-1

Since, Cell constant remain same for both systems X and Y electrolyte as same conductivity cell is used therefore

Cell constant

= Conductivity x Resistance

= (100 ohm-1) x (1.0x 10-4 ohm-1 cm-1)

= 10-2 cm-1

Part-2

Conductivity of 0.01 M solution of Y = ?

Resistance of a conductivity cell with electrolyte Y = 50 ohms

Cell constant = = 10-2 cm-1

Therefore,

Conductivity

= 10-2 cm-1 /50 ohm

= 0.0002 Scm-1

Part-3

Molar conductivity of 0.01 M solution Y

Molar conductivity

= K/c

= 0.0002 Scm-1 / 0.01 M

= 0.02 M-1Scm-1