NEET-XII-Chemistry

exam-1 year:2016

with Solutions -
  • #55
    MY and ``NY_3``, two nearly insoluble salts, have the
    same ``K_{sp}`` values of 6.2 × ``10^{-13}`` at room
    temperature. Which statement would be true in
    regard to MY and ``NY_3`` ?
    (1) The molar solubilities of MY and ``NY_3`` in water
    are identical.
    (2) The molar solubility of MY in water is less than
    that of ``NY_3``
    (3) The salts MY and ``NY_3`` are more soluble in
    0.5 M KY than in pure water.
    (4) The addition of the salt of KY to solution of MY
    and ``NY_3`` will have no effect on their solubilities.
    digAnsr:   2
    Ans : (2)
    Sol.  = 2spMY K s = 6.2 × 10-13
    =  13s 6.2 10
    s = 7.87 × 10-7 mol L-1
    NY3 ï‚® Ksp = 27 s
    4 = 6.2 × 10-13
     
    =  
     
    1/4136.2 10
    s
    27
    s = 3.89 × 10-4 mol L-1
    ∴ molar solubility of NY3 is more than MY in wa-
    ter.