Fractional Precipitation Pogil Answer Key -

AgCl(s)⇌Ag+(aq)+Cl−(aq)(Ksp=1.8×10-10)AgCl open paren s close paren is in equilibrium with Ag raised to the positive power open paren a q close paren plus Cl raised to the negative power open paren a q close paren space open paren cap K sub s p end-sub equals 1.8 cross 10 to the negative 10 power close paren

Find ([Cl^-]) when ([Ag^+] = 1.0\times 10^-5) M (complete precipitation): [ [Cl^-] = \fracK_sp(AgCl)[Ag^+] \textfinal = \frac1.8\times 10^-101.0\times 10^-5 = 1.8\times 10^-5 \text M ] At this ([Cl^-]), check if (PbCl_2) has started: (Q = [Pb^2+][Cl^-]^2 = (0.10)(1.8\times 10^-5)^2 = 3.24\times 10^-11) Compare to (K sp(PbCl_2) = 1.7\times 10^-5). (Q \ll K_sp), so (Pb^2+) is still in solution. Separation is possible.

values of the two competing compounds differ by several orders of magnitude. fractional precipitation pogil answer key

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

) at equal concentrations. A dropping funnel introduces a cation (e.g., Ag+cap A g raised to the positive power AgCl(s)⇌Ag+(aq)+Cl−(aq)(Ksp=1

| Ion pair | (K_sp) values | Which precipitates first? | [anion] to start 1st ppt | [anion] to start 2nd ppt | % of 1st ion left when 2nd starts | |----------|----------------|------------------------|------------------------|------------------------|----------------------------------| | AgCl ((K_sp=1.8\times10^-10)), AgI ((8.3\times10^-17)) | ... | ... | ... | ... | ... | | CaF₂ ((3.9\times10^-11)), SrF₂ ((2.9\times10^-9)) | ... | ... | ... | ... | ... |

starts to precipitate. This indicates an exceptionally successful quantitative separation. Tips for Mastering POGIL Chemistry Activities values of the two competing compounds differ by

This calculation proves the effectiveness of the separation: nearly all the chloride ions have been removed from the solution before any chromate begins to precipitate. Tips for Completing Your POGIL Worksheet

: The solution is supersaturated. A precipitate will actively form until Kspcap K sub s p end-sub Step-by-Step Fractional Precipitation Calculations

Fractional precipitation separates ions in solution by exploiting differences in their solubility products ((K_sp)). When a common precipitating agent is added, the less soluble compound (smaller (K_sp)) precipitates first.

Many "Level 3" POGIL questions ask how much of the first ion remains in solution when the second ion begins to precipitate. To solve this, take the

AgCl(s)⇌Ag+(aq)+Cl−(aq)(Ksp=1.8×10-10)AgCl open paren s close paren is in equilibrium with Ag raised to the positive power open paren a q close paren plus Cl raised to the negative power open paren a q close paren space open paren cap K sub s p end-sub equals 1.8 cross 10 to the negative 10 power close paren

Find ([Cl^-]) when ([Ag^+] = 1.0\times 10^-5) M (complete precipitation): [ [Cl^-] = \fracK_sp(AgCl)[Ag^+] \textfinal = \frac1.8\times 10^-101.0\times 10^-5 = 1.8\times 10^-5 \text M ] At this ([Cl^-]), check if (PbCl_2) has started: (Q = [Pb^2+][Cl^-]^2 = (0.10)(1.8\times 10^-5)^2 = 3.24\times 10^-11) Compare to (K sp(PbCl_2) = 1.7\times 10^-5). (Q \ll K_sp), so (Pb^2+) is still in solution. Separation is possible.

values of the two competing compounds differ by several orders of magnitude.

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

) at equal concentrations. A dropping funnel introduces a cation (e.g., Ag+cap A g raised to the positive power

| Ion pair | (K_sp) values | Which precipitates first? | [anion] to start 1st ppt | [anion] to start 2nd ppt | % of 1st ion left when 2nd starts | |----------|----------------|------------------------|------------------------|------------------------|----------------------------------| | AgCl ((K_sp=1.8\times10^-10)), AgI ((8.3\times10^-17)) | ... | ... | ... | ... | ... | | CaF₂ ((3.9\times10^-11)), SrF₂ ((2.9\times10^-9)) | ... | ... | ... | ... | ... |

starts to precipitate. This indicates an exceptionally successful quantitative separation. Tips for Mastering POGIL Chemistry Activities

This calculation proves the effectiveness of the separation: nearly all the chloride ions have been removed from the solution before any chromate begins to precipitate. Tips for Completing Your POGIL Worksheet

: The solution is supersaturated. A precipitate will actively form until Kspcap K sub s p end-sub Step-by-Step Fractional Precipitation Calculations

Fractional precipitation separates ions in solution by exploiting differences in their solubility products ((K_sp)). When a common precipitating agent is added, the less soluble compound (smaller (K_sp)) precipitates first.

Many "Level 3" POGIL questions ask how much of the first ion remains in solution when the second ion begins to precipitate. To solve this, take the