Question
The conductivity of a weak acid HA of concentration 0.001 ~mol ~L ^ -1 is 2.0 10^ -5 ~S ~cm ^ -1 . If _ m ^ ( HA )=190 ~S ~cm ^2 ~mol ^ -1 , the ionization constant ( K _ a ) of HA is equal to _______ x 10^ -6 .
BITSAT
Chemistry
Electrochemistry
2023
BITSAT 2023 (Memory Based Paper 1)
BITSAT Chemistry Question (2023) — Solution
Options
- A. 24
- B. 48
- C. 12
- D. 45
Answer
C. 12
Step-by-step solution
_ m =1000 K M =1000 2 10^ -5 0.001 =20 ~S ~cm ^2 ~mol ^ -1 = _ m _ m ^ = 20 190 = ( 2 19 ) 0.001(1- ) HA 0.001 H ^ + + 0.001 A ^ - K_ a =0.001 ( ^2 1- )= 0.001 ( 2 19 )^2 1- ( 2 19 ) =12.3 10^ -6
Related: Chemistry — Electrochemistry · All PYQ Banks