Question

11. A conductivity cell bas its electrodes 1 cm apart
and each electrode has area of cross-section 2
cm. When filled with N/50 MX, the cell shows a
resistance of 166.5 ohms. Calculate the equivalent
conductance of MX at the given concentration.​

Answer 1

Given that,

Area = 2 cm

Length = 1 cm

Resistance = 166.5 ohms

Solution of MX= $\dfrac{N}{50}$

Solution of MX= 0.02 N

We need to calculate the volume

0.02 N solution means 0.02 g equivalent are present in 1000 mL.

So, 1 g  equivalent will be present in Volume

$V=\dfrac{1000}{0.02}$

$V=50000\mL$

We need to calculate the specific conductivity

Using formula of specific conductivity

$k=\dfrac{l}{A\times R}$

Put the value into the formula

$k=\dfrac{1}{2\times166.5}$

$k=3\times10^{-3}\ mho/cm$

We need to calculate the equivalent  conductivity

Using formula of conductivity

$\Lambda=k\times V$

Put the value into the formula

$\Lambda=3\times10^{-3}\times50000$

$\Lambda=150\ mho\ cm^2/eq$

Hence, The equivalent  conductance of MX is $150\ mho\ cm^2/eq$