Скачать или смотреть The precipitate of CaF₂ (Ksp = 1.7 × 10⁻¹⁰) is obtained when equal volumes of which of the following

Solubility product (Ksp), common ion effect, ionic equilibrium, precipitation – these are the primary concepts involved in this problem. Precipitation occurs when the ionic product (IP) of the constituent ions in a solution exceeds the Ksp of the salt. For CaF₂, which dissociates as CaF₂ ⇌ Ca²⁺ + 2F⁻, the expression for Ksp is [Ca²⁺] × [F⁻]². Understanding this equilibrium is key to predicting whether a precipitate will form.

When equal volumes of two ionic solutions are mixed, the concentration of each ion is halved due to dilution. Therefore, the new concentrations must be used to compute the ionic product. To check for precipitation, calculate the IP as [Ca²⁺]/2 × ([F⁻]/2)² and compare it with the given Ksp value (1.7 × 10⁻¹⁰). If IP greater than Ksp, a precipitate of CaF₂ will form. This type of calculation is vital in inorganic chemistry and analytical applications, such as qualitative cation analysis.

The solubility product concept helps predict the solubility of sparingly soluble salts and determines the minimum concentrations needed to cause precipitation. It also explains why increasing the concentration of one ion can shift the equilibrium, driving the precipitation of a salt. These principles are foundational in understanding salt solubility, particularly in fields like medicine, environmental chemistry, and metallurgy.

Question Text:
The precipitate of CaF₂ (Ksp = 1.7 × 10⁻¹⁰) is obtained when equal volumes of which of the following are mixed?

(a) 10⁻⁴ M Ca²⁺ + 10⁻⁴ M F⁻
(b) 10⁻² M Ca²⁺ + 10⁻³ M F⁻
(c) 10⁻⁵ M Ca²⁺ + 10⁻³ M F⁻
(d) 10⁻³ M Ca²⁺ + 10⁻⁵ M F⁻