Copyright 2018 Dan Dill 1

Size: px

Start display at page:

Carmel Hunt
5 years ago
Views:

1 TP sp for M 2 X 2 M X 2 is Assume a maximum of moles of M 2 X can dissolve in one liter. What is true for? 1. sp 2 2. sp sp 2 4. None of the above Lecture 22 CH102 A2 (MWF 11:1 am) Wednesday, March 21, 2018 Complete: Five kinds of solubility equilibria problems Practice with solubility equilibria Next lecture: Begin ch16: Electron transfer reactions and electrochemistry. For oxidation numbers and balancing redox equations, please work through From solubility get K sp Ch1: Solubility, precipitation, and complexation The solubility of magnesium phosphate is g/100 g of water at 20. Calculate its sp at this temperature. Mg 3 PO Mg 2 2 PO 3 4 M 3 X 2 M 2 X 3 Initial excess

2 2. From solubility get K sp The solubility of magnesium phosphate is g/100 g of water at 20. Calculate its sp at this temperature. Mg 3 PO Mg 2 2 PO 4 3 M 3 X 2 M 2 X 3 Initial excess excess g/100 g mol/l sp M 2 3 X Answer: Calculate the molar solubility in a solution of 0.01 M NaF. 8 Calculate the molar solubility in a solution of 0.01 M NaF. Calculate the molar solubility in a solution of 0.01 M NaF. Initial Initial excess 0 c ion

3 Calculate the molar solubility in a solution of 0.01 M NaF. 4. Will precipitation occur? 0.2 mmol of NaF and 10 mmol of Ca NO 3 2 are combined in a total volume of 1 L of water. Will a precipitate form? The sp of CaF 2 is Initial excess 0 c ion 2 excess c ion 2 c ion K sp M 2 X 2 c ion 2 Large c ion makes x smaller Answer: , 0.08 % of the value in pure water! Initial Will precipitation occur? 0.2 mmol of NaF and 10 mmol of Ca NO 3 2 are combined in a total volume of 1 L of water. Will a precipitate form? The sp of CaF 2 is When 0.2 mmol of NaF and 10 mmol of Ca NO 3 2 are combined in 1 L of water, sp of CaF 2 is Initial 0 c M c X Is M 2 X 2 c M c X 2 sp sp? If no, then no precipitation. If yes, then a precipitate will form. Answer: sp sp, so CaF 2 will precipitate

4 When 0.2 mmol of NaF and 10 mmol of Ca NO 3 2 are combined in 1 L of water, Initial mol Revised M Initial mol mol mol Revised M 1 16 Initial mol mol mol Revised M mol mol/v 0 Initial mol mol Revised mol mol/v 0/V

5 Initial mol mol Revised mol mol/v 0/V mol mol/v 2 Initial mol mol Revised mol mol/v 0/V mol mol/v 2 19 K sp M 2 X y 2 Answer: Ca M, F 2 y M Check: Q sp K sp 20 Practice with solubility equilibria TP The expression for the equilibrium constant for the solubility equilibrium M 2 X 2 M X 2 is 1. sp 2 M X 2 / M 2 X 2. sp 2 M 2 X 2 / M 2 X 3. sp 2 M 2 X 2 4. sp M 2 X

6 TP sp for M 2 X 2 M X 2 is Assume a maximum of moles of M 2 X can dissolve in one liter. What is true for? 1. sp 2 2. sp sp 2 4. None of the above Quiz sp for M 2 X 2 M X 2 is Assume a maximum of y moles of M 2 X can dissolve in one liter. What is true for if M is initially 0.1 M that is, M is a common ion? 1. sp sp sp sp 0.1. None of the above

Copyright 2016 Dan Dill 1

Copyright 2016 Dan Dill 1 carbonate These solutions are mixed and a precipitate forms. After the precipitation, the solution 1. will be positively charged 2. will be electrically neutral 3. will be negatively charged 4. More information