Question

Consider 0.10 M solutions following acids: HF, Ka = 6.8x10-4 HIO, K2 = 2.3x10-11 HC7H502, Ka = 6.3x10-5 HCOOH, K = 1.8x10-4 Which of the following statements is true? HC7H5O2 has the lowest pH and the largest percent dissociation. HF has the highest pH and the largest percent dissociation. HCOOH has the lowest pH and the largest percent dissociation. HIO has the highest pH and the smallest percent dissociation. HF has the lowest pH and HIO has the largest percent dissociation.

Answer 1

Ka is the measure of acidity of a acid. The more is. the Kavalue, the more ran goes in forward direction. le. And dissociates more and give more H ie. more acidic ka HA Ht to so ka more - acidity of acid more and less pH value Arranging the acids in increasing Ka value: Ka value:- HIO LHC7 H5 Og <HCOOK CHF 2.3x10-11 6.3x105 1-8x10 6.8 X 10 1 pH value:- HIO > HG, H5027 HCOOH THE 1% dissociation - HIO CHEZ H50g <HCool CHF So according to options we have the 4th option right- AS HIO has highest pH and smallest % dissociation 250g (g) + O2(g) 2503 (9) Kc = 1.7 X 10° SO Reversing the ran, The new Kc ce Kc = 2 For ranit Kc 2503 (9) 250 2(g) + 02 (9) Kc = 1 BE 1.7 X 106 6 = 5 88 × 1 By multiplying the equation by factor II the ran becomes - SO3 (9) S0g (g) + 1 Og (9) Keris ils eqbom const New=Kc" = (Kc) 2 - (5.88 x 10-5207669x10 3 or 7.669810 egb const Ans = option to- 7-78 109