1 (531)

Prévia do material em texto

17 Additional Aspects of Solutions to Exercises Aqueous Equilibria CaC₂O₄(s) = 1.00 L soln 1 mol = 4.76 10⁻⁵ = 4.8 X 10⁻⁵ M 17.54 PbI₂(s) 11 0.54 1.00 soln X 461.0 1 mol PbI₂ = 1.17 X 10⁻³ = 1.2 10⁻³ M 17.55 Analyze/Plan. Follow the logic in Sample Exercises 17.11 and 17.12. Solve. (a) AgBr(s) 1L (b) Molar solubility = = [Br⁻]; = 0.030 M + ≈ 5.0 X 10⁻¹³ = 0.030(x); = 10⁻¹¹ mol AgBr/L (c) Molar solubility = = There are two sources of Br⁻: NaBr(0.10 M) and AgBr(x M) = (x)(0.10 + x); Assuming is small compared to 0.10 M ≈ 17.56 LaF₃(s) = (a) molar solubility = = [La³⁺]; [F⁻] = 3x 9.28 X 10⁻⁶ mol LaF₃ 195.9 LaF₃ = 1.82 10⁻³ = 2 X 10⁻³ g LaF₃/L 1L 1 mol (b) molar solubility = = [La³⁺] There are two sources of KF(0.010 M) and LaF₃ (3x M) = + assume is small compared to 0.010 M. 2 = (0.010)³ x; = 2 X X = 2 X 10⁻¹³ M 2 X 10⁻¹³ mol LaF₃ 195.9 LaF₃ = 3.92 X 10⁻¹¹ = 4 X 10⁻¹¹ g LaF₃/L 1L 1 mol 525