Fractional: Precipitation Pogil Answer Key

POGILs are notorious for being picky about sig figs. Ensure your calculations match the precision of the data given in the "Model" diagrams.

If you know the concentration of the ion already in the beaker, you solve for the concentration of the ion you are adding. Precipitation begins the moment the exceeds the Kspcap K sub s p end-sub . 3. Determining Which Ion Precipitates First A classic POGIL question might look like this: "A solution contains 0.10 M Cl−cap C l raised to the negative power and 0.10 M Br−cap B r raised to the negative power Ag+cap A g raised to the positive power is added, which silver salt forms first?" Step 1: Look up Kspcap K sub s p end-sub AgClcap A g cap C l AgBrcap A g cap B r Step 2: Calculate the needed to precipitate each. Answer: Since AgBrcap A g cap B r has a much lower Kspcap K sub s p end-sub fractional precipitation pogil answer key

Let me know the specific Kspcap K sub s p end-sub POGILs are notorious for being picky about sig figs

Ksp=[Cation]×[Anion]cap K sub s p end-sub equals open bracket cap C a t i o n close bracket cross open bracket cap A n i o n close bracket Precipitation begins the moment the exceeds the Kspcap

By carefully controlling the concentration of the precipitating agent, you can force the least soluble salt to drop out of the liquid while keeping the more soluble ions in the solution. Core Concepts You’ll Find in the POGIL 1. The Role of Kspcap K sub s p end-sub Kspcap K sub s p end-sub

(or other precipitating ion) required for the second salt and plug it back into the Kspcap K sub s p end-sub expression of the first salt. Why You Shouldn't Just Copy the Answer Key

values directly; you must calculate the required concentration of the common ion for each.