Step-I : 0.5 litre of saturated Mg ( OH ) 3 ( aq ) is in contact with Mg ( OH ) 2 ( s ) .Step-II : Step-II: 0.5 litre of H₂O is added to 0.5 liter of solution in Step (I), and the solution is vigo

Question

Step-I : 0.5 litre of saturated Mg ( OH ) 3 ​ ( aq ) is in contact with Mg ( OH ) 2 ​ ( s ) .Step-II : Step-II: 0.5 litre of H₂O is added to 0.5 liter of solution in Step (I), and the solution is vigorously stirred; undissolved Mg(OH)₂(s) remains. Step-III: 100 mL of the clear solution in Step (II) is taken and added to 0.5 litre of 0.1 M HCl(aq). Step-IV: 25 mL of the clear solution in Step (III) is taken and added to 225 mL of 0.060 M MgCl₂(aq). ( K s p ​ for Mg(OH)₂ = 3.2 × 1 0 − 11 ). Which of the following are correct choices about the above steps?

TestHub · Accepted Answer

Mg ( OH ) 2 ​ ( s ) ⇌ Mg 2 + ( aq ) + 2 OH − ( aq ) K sp ​ = [ Mg 2 + ] [ OH − ] 2 = 4 s 3 = 3.2 × 1 0 − 11 ∴ s = 2 × 1 0 − 4 M ∴ Concentration of Mg ( OH ) 2 ​ in step (I) solution = 2 × 1 0 − 4 M . ∴ Concentration of Mg ( OH ) 2 ​ in step (II) solution = 2 × 1 0 − 4 M Step (III) : After mixing of two solution [ Mg 2 + ] = 600 2 × 1 0 − 4 × 100 ​ = 3 1 ​ × 1 0 − 4 M Step (IV) : After mixing of two solution [ Mg 2 + ] = 250 ( 2 × 1 0 − 4 × 25 ) × ( 0.06 × 225 ) ​ = 0.054 M . [ OH − ] = 250 4 × 1 0 − 4 × 25 ​ = 4 × 1 0 − 5 ∴ I.P. = 0.054 × ( 4 × 1 0 − 5 ) 2 = 8.64 × 1 0 − 11 > K sp ​ So, precipitation of Mg ( OH ) 2 ​ will take place.

Chemistry - Ionic Equilibrium Question with Solution | TestHub

Options:(select one or more)

Doubts & Discussion