Solution

Asked by brijk456 | 3rd Sep, 2019, 12:07: AM

Expert Answer:

Correct option is (3)
Given:
 
pKa = 4
 
We know,
 
pKa = −log pKa 
 
  Ka = 10−4 
 
It is monobasic acid,
 
space space space space space space space space space space space space space space space space space space space space space space HA space space space space rightwards harpoon over leftwards harpoon space space space space space straight H to the power of plus space plus space space space straight A to the power of minus

initial space mole space space space 0.01 space

At space eqm space space space space space space open parentheses 0.01 minus straight x close parentheses straight M space space space space space open parentheses xM close parentheses space space space space space open parentheses xM close parentheses
 
straight K subscript straight a space equals fraction numerator straight x squared over denominator 0.01 end fraction space

space space space space space equals space 10 to the power of 4

straight x squared space equals space space 10 to the power of negative 2 end exponent

straight x space space equals space 0.1
 
We know van't Hoff factor is,
 
straight i space equals fraction numerator T o t a l space n o space o f space m o l e s space o f space p a r t i c l e s space a f t e r space d i s s o c i a t i o n over denominator T o a t l space n o. space o f space m o l e s space o f space p left square bracket a r t i c l e s space b e f o r space d i s s o c i a t i o n end fraction

space equals space fraction numerator 1 minus straight x plus straight x plus straight x over denominator 1 end fraction

equals 1 plus 0.1

straight i space equals 1.1
 
 
van't Hoff factro is 1.1

Answered by Varsha | 3rd Sep, 2019, 12:28: PM