[Ag+]=1.8×10-9Mopen bracket cap A g raised to the positive power close bracket equals 1.8 cross 10 to the negative 9 power space cap M Since is smaller than , the AgBrcap A g cap B r will precipitate first. 4. How "Complete" is the Separation?
[Br−]=2.7×10-4Mopen bracket cap B r raised to the negative power close bracket equals 2.7 cross 10 to the negative 4 power space cap M This tells you that by the time AgClcap A g cap C l starts to form, the concentration of Br−cap B r raised to the negative power has dropped from . That is a very successful separation! 5. Tips for Success If a salt is X2Ycap X sub 2 cap Y , remember that the Kspcap K sub s p end-sub expression is fractional precipitation pogil answer key best
(1.8×10-9)[Br−]=5.0×10-13open paren 1.8 cross 10 to the negative 9 power close paren open bracket cap B r raised to the negative power close bracket equals 5.0 cross 10 to the negative 13 power [Ag+]=1
Fractional precipitation is a laboratory technique used to separate two or more ions from a solution by adding a reagent that forms a precipitate with each ion. The "trick" lies in the fact that different salts have different solubilities (represented by Kspcap K sub s p end-sub [Br−]=2