Strontium, Sr, is a heavy metal that frequently causes concern when it is presen
ID: 973337 • Letter: S
Question
Strontium, Sr, is a heavy metal that frequently causes concern when it is present in water. Some preliminary calculations are necessary to detetmine whether it is feasible to precipitate Sr+ as the sulfate, Given that 10 mole/ liter of Sr and 10- mole/liter of SO are originally present and that pK. 7.8 for SrSOus (a) How much Sr will precipitate (moles/liter) i1 x 10 mole Na,SO, is added per liter of solution? and Sr remain after precipitation? (c) Aasuming that the residuals calculated in part (b) are eatisfactory, what (b) How much SO factors should be studled experimentally to determine the teasibility of the process?Explanation / Answer
Given,
Concentration of Sr+2, SO4-4 in solution = 10-4 moles per litre.
Solubility of SrSO4 in presence of1x10-3 moles per litre of Na2SO4 solution is,
Ksp = [Sr+2][SO4-4]
1.584 x10-8 = [S][S+10-3]
Where S is solubility of salt and given pKsp =7.8, Ksp = 1.584x10-8 .
Solving for S = 1.55 x10-5
Answer A:
Amount of Sr+ precipitated = 10-4 - 1.55 x10-5=8.45 x10-5 moles
Answer B)
Amount of Sr+2 remaining = amount of SO4-2 remaining =1.55 x10-5 moles per litre
Answer C:
The factors like temperature should remain constant for the above accurate results which match with experimental values.