Which of the following compounds precipitates from a...

Which of the following compounds precipitates from a solution that has the concentrations indicated? (See Appendix J for $K_{\mathrm{sp}}$ values.) (a) $\mathrm{CaCO}_{3} :\left[\mathrm{Ca}^{2+}\right]=0.003 M,\left[\mathrm{CO}_{3}^{2-}\right]=0.003 \mathrm{M}$ (b) $\mathrm{Co}(\mathrm{OH})_{2} :\left[\mathrm{Co}^{2+}\right]=0.01 M,\left[\mathrm{OH}^{-}\right]=1 \times 10^{-7} M$ (c) $\mathrm{CaHPO}_{4} :\left[\mathrm{Ca}^{2+}\right]=0.01 M,\left[\mathrm{HPO}_{4}^{2-}\right]=2 \times 10^{-6} \mathrm{M}$ (d) $\mathrm{Pb}_{3}\left(\mathrm{PO}_{4}\right)_{2} :\left[\mathrm{Pb}^{2+}\right]=0.01 \mathrm{M},\left[\mathrm{PO}_{4}^{3-}\right]=1 \times 10^{-13} \mathrm{M}$

Which of the following compounds precipitates from a solution that has the concentrations indicated? (See Appendix J for $K_{\mathrm{sp}}$ values.)
(a) $\mathrm{CaCO}_{3} :\left[\mathrm{Ca}^{2+}\right]=0.003 M,\left[\mathrm{CO}_{3}^{2-}\right]=0.003 \mathrm{M}$
(b) $\mathrm{Co}(\mathrm{OH})_{2} :\left[\mathrm{Co}^{2+}\right]=0.01 M,\left[\mathrm{OH}^{-}\right]=1 \times 10^{-7} M$
(c) $\mathrm{CaHPO}_{4} :\left[\mathrm{Ca}^{2+}\right]=0.01 M,\left[\mathrm{HPO}_{4}^{2-}\right]=2 \times 10^{-6} \mathrm{M}$
(d) $\mathrm{Pb}_{3}\left(\mathrm{PO}_{4}\right)_{2} :\left[\mathrm{Pb}^{2+}\right]=0.01 \mathrm{M},\left[\mathrm{PO}_{4}^{3-}\right]=1 \times 10^{-13} \mathrm{M}$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Solubility Product Constant (Ksp)

The Ksp is a numerical value that represents the product of the concentrations of the ions in solution at equilibrium for a sparingly soluble salt. It is a measure of the maximum ion concentration that can exist in solution without the solid dissolving further, and it is fundamental in predicting whether a precipitate will form under given conditions.

Reaction Quotient (Q) and Its Comparison to Ksp

The reaction quotient (Q) is calculated similarly to the Ksp expression but using the current concentrations of ions in the solution. By comparing Q to the Ksp, one can determine whether a solution is undersaturated (Q < Ksp), saturated (Q = Ksp), or supersaturated (Q > Ksp). A supersaturated solution indicates that a precipitate will form.

Stoichiometry in Precipitation Reactions

Stoichiometry plays a vital role in setting up the Ksp expression correctly, as it requires the proper incorporation of the coefficients from the balanced dissolution equation. This ensures that the calculation of the ionic product reflects the true contribution of each ion, which is crucial in predicting precipitation accurately.

Transcript

Please give Ace some feedback