Fractional Precipitation Pogil Answer Key (Certified)

Here is how to determine which compound precipitates first and calculate the remaining concentration of the first ion. Step 1: Write out the Equilibrium Expressions

When two or more ions that can form precipitates with the same counter-ion are present in a solution, they will not precipitate at the same time. The compound with the lower solubility will precipitate first when a precipitating agent is slowly added.

Hg₂Cl₂ and possibly some AgCl precipitate, but PbCl₂ remains dissolved.

Fractional Precipitation POGIL Answer Key: A Comprehensive Guide to Selective Ion Separation fractional precipitation pogil answer key

8.5×10-17=(1.8×10-9 M)×[I−]8.5 cross 10 to the negative 17 power equals open paren 1.8 cross 10 to the negative 9 power M close paren cross open bracket I raised to the negative power close bracket

Answer-key style checklist for each POGIL question

Before diving into the POGIL answers, let’s establish the foundational chemistry. Here is how to determine which compound precipitates

Example B — Carbonate precipitation of Zn2+ and Cu2+ (common POGIL)

Process Oriented Guided Inquiry Learning (POGIL) worksheets are designed to guide you toward these conclusions without a teacher directly lecturing you. If you are working through a fractional precipitation POGIL worksheet, keep these strategies in mind to find the correct answers:

[Ag+]required for Ag2CrO4=Ksp(Ag2CrO4)[CrO42−]open bracket Ag raised to the positive power close bracket sub required for Ag sub 2 CrO sub 4 end-sub equals the square root of the fraction with numerator cap K sub s p end-sub open paren Ag sub 2 CrO sub 4 close paren and denominator open bracket CrO sub 4 raised to the 2 minus power close bracket end-fraction end-root Step 3: Identify the First Precipitate Compare the two calculated values for Hg₂Cl₂ and possibly some AgCl precipitate, but PbCl₂

Looking for more POGIL answer keys or chemistry study guides? Check out our other articles on solubility equilibrium, common ion effect, and acid-base titration POGILs.

Write out the balanced dissolution equations and their corresponding equilibrium expressions for both potential precipitates.

[Cl−]remaining=Ksp of AgCl[Ag+]=1.8×10-103.46×10-6 M=5.2×10-5 Mopen bracket cap C l raised to the negative power close bracket sub remaining end-sub equals the fraction with numerator cap K sub s p end-sub of cap A g cap C l and denominator open bracket cap A g raised to the positive power close bracket end-fraction equals the fraction with numerator 1.8 cross 10 to the negative 10 power and denominator 3.46 cross 10 to the negative 6 power M end-fraction equals 5.2 cross 10 to the negative 5 power M

To find the exact concentration needed to start precipitation, set and solve for For :