The resistance of `1/10` M solution is `2.5xx10^(3)` ohm. What is the molar conductivity of solution? (cell constant= 1.25 `cm^(-1)`)

Options

A. `3.5 ohm^(-1)cm^(2)mol^(-1)`
B. `5.0 ohm^(-1)cm^(2)mol^(-1)`
C. `2.5 ohm^(-1)cm^(2)mol^(-1)`
D. `2.0 ohm^(-1)cm^(2)mol^(-1)`

Answer

B

Explanation

Given, Molarity `=1/10`M
`R=2.5xx10^(3)Omega`
Cell constant `(l/a)=1.25cm^(-1)`
Now, k(conductivity)`=1/kxx1/a`
`thereforek=1/(2.5xx10^(3))xx1.25=0.5xx10^(-3)Omega^(-1)cm^(-1)`
`rArr`Molar conductivity`(wedge_(m))=(kxx1000)/M`
`thereforewedge_(m)=(0.5xx10^(-3)xx1000)/(1//10)`
`wedge_(m)=5Omega^(-1)cm^(2)mol^(-1)`