03 Jul, 2021 10:03 PM

Calculate the molar solubility of CuX Ksp = 1.27 x 10^-36 in each of the following.?

0.27M CuCl2 0.19M Na2X

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AN
03 Jul, 2021 10:04 PM

CuX = Cu2+ + X2-

Ksp  =  [Cu2+] * [X2-]

for each mole of CuX that dissolves we get x mol of each of the anions and cations

Ksp = x^2 = 1.27 x 10 ^-36

x= 1.13 x 10 ^-18 moles of CuX per liter of pure water 

if the solution has [Cu2+]= 0.27 M

Ksp becomes x ( x + 0.27) 

as we can see above x is extremely small so can be ignored inside the brackets 

0.27 x =  1.27 x 10^-36

x = 1.27 x 10^-36 / 0.27 = 4.70 x 10 ^-36 moles per liter

In 0.19M X2- we have 

Ksp = 0.19x =  1.27 x 10^-36 

x =  1.27 x 10^-36 / 0.19 =   6.68 x 10 ^-36 moles per liter 

PA
03 Jul, 2021 10:04 PM

update

in 0.23M Na2X

S = 5.5x10^-36