AirCowPeaCock - 22-1-2012 at 13:57
According to the wiki SrSO4 has very low solubility in water ~0.01 g/100 ml. It also says it has greater solubility in nitric acid. But how much
greater? less than 1g per L?
AJKOER - 22-1-2012 at 14:19
HNO3 could react with SrSO4 slowly forming, undoubtedly, a soluble nitrate and H2SO4.
My speculation is greater than 1g per liter, perhaps approaching 60g per liter, the same as Sr(NO3)2.
UnintentionalChaos - 22-1-2012 at 14:50
This is simply a product of Ksp.
SrSO4(s) <--> Sr+2(aq) + SO4-2(aq)
Ksp=[Sr+2][SO4-2]
If you are in a strongly acidic environment, you'll partially protonate the SO4-2 to HSO4- and H2SO4, reducing the effective concentration of SO4-2.
In order to compensate, more SrSO4 will dissolve so that Ksp=[Sr+2][SO4-2] still holds true. However, [Sr+2] and [SO4-2] will no longer have the same
value. There is an equation to calculate exactly how protonated the SO4-2 will be based on [H+] and the Ka values, but I can never find it online when
I need it.
Exactly how much will dissolve depends thus, on how concentrated the nitric acid is and the quantitative math probably falls apart with significantly
concentrated HNO3. This is valid for fairly dilute (maybe up to a few molar) solutions.
AirCowPeaCock - 22-1-2012 at 20:50
Okay, that helps--a little. But I certainly don't think its going to be anywhere near 60g/L, not based on what we see for its solubility in water
0.003g/L