ChemCollective-Virtual-Labs/C3/Determination-of-Solubility-Product/English-timed

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Time Narration
00:01 Welcome to this spoken tutorial on Determination of Solubility Product using Vlabs.
00:08 In this tutorial we will learn to, Determine Solubility of salts and

Calculate Solubility Product of various sparingly soluble salts.

00:20 Here, I am using

Mac OS version 10.10.5

00:26 ChemCollective Vlabs version 2.1.0 and

Java version 8.0

00:34 To follow this tutorial you should be familiar with,

Chemcollective vlabs interface.

00:41 If not for relevant tutorials, please visit our website.
00:47 Here, I have opened Virtual Chemistry labs application window.
00:53 Click on File menu and select Load Homework option.

Default Lab Setup dialog-box opens.

01:02 Double-click on Solubility and Solids option.

From the sub-menu, double-click on Determining the solubility product option.

01:13 A workbench opens with required chemicals and Problem Description.
01:19 Under the Stockroom Explorer double click on Problem Description.
01:26 Problem Description window opens.
01:30 The problem states that, using Virtual labs, We have to determine Solubility Products of

Silver chloride

Strontium Sulphate

Silver Carbonate and

Strontium Iodate.

01:47 We have to also find the solubility of the above salts in Moles/Litre.
01:54 Finally we have to compare the Solubility and Solubility Products for pairs of salts.
02:02 Close the Problem Description window.
02:05 A substance's solubility product, is the mathematical product of its dissolved ion concentrations raised to the power of their stoichiometric coefficients.
02:18 For Example: Solubility of Silver Chloride in its saturated solution is given as follows:
02:26 For every one mole of silver chloride that dissolves, one mole of silver ion and one mole of chloride ion is produced.
02:37 Let us assign a variable S to represent solubility of Silver and Chloride ions.
02:44 Solubility Product of silver chloride is S squared.
02:49 Here is the solubility of Silver carbonate in its saturated solution.
02:55 Stoichiometric concentrations of the ions are in the ratio of 2 : 1
03:01 In this equation, solubility of silver ion is two S and carbonate ion is S.
03:09 Solubility Product of silver carbonate is four S cube.
03:15 Significance of Solubility Product.

Solubility Product applies to solutions where salts do not fully dissolve.

03:24 Water is generally used as a solvent.

Solubility Product changes with temperature.

03:32 Solubility Product is a heterogeneous equilibrium constant.
03:37 The smaller the Solubility Product of a substance, the lower is its solubility.
03:43 Solubility Product values are useful in predicting, the precipitation in reactions.
03:50 When the Ionic product is greater than Solubility Product, then precipitation will occur.
03:57 When the Ionic product is smaller than Solubility Product, then precipitation will not occur.
04:04 Back to the workbench.

From the Stockroom Explorer, double-click to select,

Silver chloride

Silver Carbonate

Strontium Sulphate and

Strontium Iodate.

04:22 Click on Select tools icon.

Click to select Scale and Weighing Boat.

04:29 For this demonstration we require 4 copies of Weighing Boats.
04:35 Right-click on the Weighing Boat.

Select Duplicate option from the context menu.

04:42 A new Weighing Boat appears.

Similarly obtain other Weighing Boats.

04:50 Rearrange the Weighing Boats on the workbench.
04:54 Let us assign names to each one of them.

Right-click on the Weighing Boat.

05:01 Select Rename option from the context menu.
05:05 Rename the Weighing Boats as 1, 2, 3 and 4.
05:15 From the Stockroom Explorer, double-click on 100 mL Distilled water flask.
05:22 100 mL Distilled water flask appears on the workbench.

Right-click on the flask.

05:30 Use Duplicate option to make 4 copies.
05:36 Rearrange 100 mL Distilled water flasks on the workbench.
05:42 Right-click on the flask, select Rename option from the context menu.

Rename the flasks as 1, 2, 3 and 4.

05:58 Bring the Scale to a convenient position on the workbench.
06:03 Place Weighing Boat 1 on the scale.

Click TARE.

06:09 Weigh 5 grams of Silver Chloride.

Bring the Silver Chloride bottle near to the Weighing Boat 1.

06:17 In the Transfer amount input bar , type 5.

Click on Pour.

06:23 Keep the Silver Chloride bottle aside.

Now let us transfer Silver Chloride to flask 1.

06:31 Bring Weighing Boat 1 to flask 1.
06:34 Type 5 in the Transfer amount input bar. Click on Pour.

Keep Weighing Boat aside.

06:43 Click on Flask 1.

Observe the Solution Info Panel.

06:48 By default Aqueous radio button is selected.
06:53 Concentrations of all the ionic species present in the solution are given here.
07:00 Click on the small black arrow, next to Molarity.
07:04 Here we can express concentrations in grams, moles and Molarity.
07:12 Note the concentrations of Silver ion and Chloride ion in terms of Molarity.
07:18 Similarly, using weighing boat, weigh 5 gm each of,

Silver Carbonate

Strontium Sulphate, and

Strontium Iodate

07:32 Pour into flasks 2, 3 and 4 respectively.
07:57 Click on each flask.

Wait till equilibrium is reached.

08:05 Note the concentrations of ions at equilibrium.
08:09 This value is the Solubility of that ion in its saturated solution.
08:15 Note solubility values for each ion in the table as shown here.
08:22 Calculate Solubility product for each salt.

Note in the table.

08:28 Solubility products values for Strontium salts are more when compared to silver salts.
08:36 This is because Strontium salts are more soluble in water when compared to silver salts.
08:44 The experimental values of Solubility Product are comparable with known values.
08:52 Let us summarize.

In this tutorial we have, Determined solubility of salts.

09:00 Calculated Solubility Product of various sparingly soluble salts.
09:06 As an assignment, For Strontium Sulphate and Strontium Iodate:

Write dissociation equation and Solubility Product expression.

09:17 Find Solubility Product of these salts at 35° C.
09:23 Observe whether dissolution of these salts is exothermic or endothermic.
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10:04 This tutorial is contributed by Snehalatha Kaliappan and Madhuri Ganapathi from IIT-Bombay.

Thank you for joining.

Contributors and Content Editors

PoojaMoolya