Write the solubility equilibrium equation for each potential precipitate. for each salt.
Fractional precipitation is a laboratory technique used to separate ions from a solution by adding a reagent that forms a precipitate with one or more of the ions. By carefully controlling the concentration of the added reagent, one can selectively precipitate one ion at a time, based on the differing solubilities of the potential precipitates. This process is a staple in analytical chemistry and is frequently explored through POGIL (Process Oriented Guided Inquiry Learning) activities to help students grasp the underlying equilibrium concepts. Understanding Fractional Precipitation
: When you add a precipitating reagent, the compound with the lowest Kspcap K sub s p end-sub (the least soluble) will typically precipitate first.
is added dropwise, the concentration of the precipitating ion (e.g., Zn2+cap Z n raised to the 2 plus power
If you are looking for specific answers to check your work, these community-verified resources provide detailed walk-throughs:
[ [\textSO 4^2-] \textstart Ba = \fracK_sp(\textBaSO_4)[\textBa^2+] = \frac1.1 \times 10^-100.10 = 1.1 \times 10^-9 , M ] [ [\textSO 4^2-] \textstart Sr = \frac3.2 \times 10^-70.10 = 3.2 \times 10^-6 , M ] Conclusion: BaSO₄ precipitates first (lower required [SO₄²⁻]).