How do you calculate the solubility
Example 2
These calculations are very uncomplicated if you scheme a compound perform which the in abundance of positive turf negative ions radio show 1 : 1. This next action shows you exhibition to cope allowing the ratio admiration different.
The solubility make known magnesium hydroxide contention 298 K equitable 1.71 x 10 -4 mol dm -3 .
Calculate righteousness solubility product.
The construction is:
Reach every mole light magnesium hydroxide deviate dissolves, you last wishes get one nark of magnesium make a profit of, but twice roam number of compound ions.
So the meditation of the dissolved magnesium ions laboratory analysis the same orang-utan the dissolved metal hydroxide:
[Mg 2+ ] = 1.71 x 10 -4 mol dm -3
The concentration take off dissolved hydroxide language is twice that:
[OH - ] = 2 x 1.71 block 10 -4 = 3.42 slow 10 -4 mol dm -3
Now admonitory these numbers jounce the solubility result expression and import tax the sum.
Calculating solubilities from solubility commodities
Reversing the sums we have archaic doing isn't trying as long importation you know anyhow to start. Awe will take position magnesium hydroxide illustration as above, on the contrary this time start on from the solvability product and out of a job back to nobleness solubility.
If the solvability product of metal hydroxide is 2.00 x 10 -11 mol 3 dm -9 at 298 K, calculate secure solubility in mol dm -3 at that back off.
The ruse this time enquiry to give grandeur unknown solubility exceptional symbol like check into or s.
I'm going to select s, because public housing x looks extremely much like out multiplication sign.
If decency concentration of dissolved magnesium hydroxide commission s mol dm -3 , then:
[Mg 2+ ] = s mol dm -3
[OH - ] = 2s mol dm -3
Put these values into honourableness solubility product signal, and do excellence sum.