Question

The resistance of `1/10`M solution is 2.5 × 10³ ohm. What is the molar conductivity of solution? (cell constant = 1.25 cm^-1).

पर्याय

• 3.5 ohm^-1 cm² mol^-1

• 5.0 ohm^-1 cm² mol^-1

• 2.5 ohm^-1 cm² mol^-1

• 2.0 ohm^-1 cm² mol^-1

Answer 1

5.0 ohm^-1 cm² mol^-1 

Explanation:

Given, Molarity = `1/10`M

R = 2.5 × 10³ Ω

Cell constant `("l"/"a")` = 1.25 cm^-1

Now, K(conductivity) = `1/"R" xx "l"/"a"`

`therefore "K" = 1/(2.5 xx 10^3) xx 1.25`

`= 0.5 xx 10^-3 Omega^-1 "cm"^-1`

`=> "Molar conductivity" (∧_"m") = ("K" xx 1000)/"M"`

`therefore ∧_"m" = (0.5 xx 10^-3 xx 1000)/(1//10)`

`∧_"m"` = 5.0 ohm^-1 cm² mol^-1