((install)) - Fractional Precipitation Pogil Answer Key 2021

Consider a solution that contains 0.1 M Ba2+ and 0.1 M Ca2+ ions. If we add a solution of NaSO4 to this solution, what will happen?

The lower the [Ag⁺] required to begin precipitation, the earlier that compound will precipitate. The answer key confirms that the ion that requires the smallest [Ag⁺] will form a solid first. This explains why, for a mixture of halides of equal concentration, AgI (Ksp = 8.3 × 10⁻¹⁷) precipitates first, followed by AgBr (Ksp = 5.0 × 10⁻¹³), and finally AgCl (Ksp = 1.8 × 10⁻¹⁰). fractional precipitation pogil answer key 2021

The 2021 POGIL likely used a classic pair: chlorides (Ag⁺, Pb²⁺, Hg₂²⁺) or hydroxides/carbonates. The key insight is that solubility isn’t binary . Things don’t suddenly become insoluble at a magic concentration. Instead, there’s a continuous range where Q (the ion product) approaches Ksp. Consider a solution that contains 0

to find the specific concentration of the precipitating agent needed to trigger the reaction. The answer key confirms that the ion that

values, meaning one is much less "willing" to stay dissolved in water than the other. 2. The First Finisher: Reaching Saturation

) : Used to determine if a precipitate will form at a given instantaneous concentration ( indicates precipitation). The experimental setup often involves adding a sodium carbonate solution (Solution B) to a mixture of zinc nitrate and copper(II) nitrate (Solution A). Cations and Anions in Solution A : Zn2+cap Z n raised to the 2 plus power Cu2+cap C u raised to the 2 plus power NO3−cap N cap O sub 3 raised to the negative power Cations and Anions in Solution B : Na+cap N a raised to the positive power CO32−cap C cap O sub 3 raised to the 2 minus power Potential Precipitates : Zinc carbonate ( ZnCO3cap Z n cap C cap O sub 3 ) and copper(II) carbonate ( CuCO3cap C u cap C cap O sub 3 Typical Answer Key Highlights

Before diving into the separation process, any POGIL activity will first ensure students understand the fundamental "rules" of solubility—. These rules govern which ionic compounds are soluble in water and which will form a precipitate (a solid).