ChemCollective-Virtual-Labs/C2/Effect-of-temperature-on-solubility/English-timed

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Time Narration
00:01 Hello everyone.

Welcome to this tutorial on Effect of Temperature on Solubility using Vlabs.

00:10 In this tutorial, we will learn

About solubility of salts with temperature.

00:16 Check if solubility is exothermic or endothermic.

Study the relationship between solubility and heat transfer.

00:26 To follow this tutorial, you should be familiar with

ChemCollective Vlabs interface.

00:33 If not for relevant tutorials please visit our website.
00:39 Here I am using

Mac OS version 10.10.5

00:45 ChemCollective Vlabs version 2.1.0

Java version 8

00:53 Here I have opened a virtual chemistry lab application window.
00:58 Go to File->Load homework option.

Select Solubility and Solids.

01:06 Click on Temperature and solubility of salts option.
01:11 Click on problem description in the stockroom explorer.
01:16 Please pause the video here and read the problem description.

Resume the video once you finish reading.

01:25 The problem has 3 sections.

In the First section: Check solubilities of Potassium chloride and Cerium(III)sulphate with temperature.

01:36 In Second section: Observe whether dissolution of Potassium chloride and Cerium sulphate is exothermic or endothermic.
01:46 In the Third section: we have to explain the observations in section 1 and 2 based on a chemical principle.
01:55 Click on Workbench.

Let us select required chemicals and apparatus for this experiment.

02:04 From the Stockroom explorer, Click on Potassium chloride, Cerius sulfate and Distilled water icons.
02:12 Click on glassware icon.

Select 50 mL Graduated Cylinder.

02:19 Again click on glassware icon.

Select 250 mL Erlenmeyer Flask.

02:27 We need two copies of 250 mL Erlenmeyer Flasks.
02:33 Use Duplicate option from the context menu to make the copies.
02:38 Click on select tools icon.

Select Scale and Weighing boat.

02:48 We need two copies of Weighing boats.

Again use Duplicate option from the context menu.

02:57 Use context menu and rename the Erlenmeyer Flasks as 1 and 2.

Similarly rename the Weighing boats as 1 and 2.

03:13 Now place each set of apparatus separately on the workbench.
03:18 Drag the Distilled water tank over to graduated cylinder.
03:23 In the Transfer amount input bar, type 50.

Click on Pour.

Keep the Distilled water aside.

03:33 Transfer 50 mL of Distilled water to flask 1 using Precise Transfer.
03:43 Keep the graduated cylinder aside.
03:46 Drag the weighing boat 1 and place it on the scale.

Click on TARE.

03:52 Drag the Potassium chloride bottle over to weighing boat 1.
03:57 Type 5 in the transfer amount input bar. Click on Pour.
04:03 Keep Potassium chloride bottle aside.
04:07 Drag the weighing boat 1 and place it on Flask 1.
04:12 In the transfer amount input bar, Type 5.

Click on pour.

04:18 Keep the weighing boat aside.
04:21 In the Solution Info Panel, click on Solid radio button.
04:26 Observe, Species and grams columns.
04:30 Since all the potassium chloride is soluble in water, there is no solid Potassium chloride in the flask.

Hence it indicates zero grams.

04:41 This indicates that potassium chloride is readily soluble in water.
04:47 Let us keep on adding Potassium chloride to flask 1 until undissolved Potassium chloride remains in flask 1.
04:57 Place the weighing boat 1 back on the Scale. Click on TARE.
05:03 Drag and place Potassium chloride bottle over weighing boat 1
05:09 Type 15 in the transfer amount input bar. Click on pour.
05:15 Keep Potassium chloride bottle aside.
05:19 Change the Transfer Bar to Realistic Transfer using Tools menu.
05:25 Drag and place weighing boat 1 over flask 1.

Click on Pour button gradually.

05:33 Observe the Solution info panel.
05:37 Observe grams column, approximately 2 grams of Potassium chloride remains undissolved.
05:45 Let us now check if increase in temperature increases or decreases the solubility.
05:52 Click on Select tool icon, choose Bunsen Burner.
05:58 Bring the Bunsen Burner close to flask 1.
06:02 Place flask 1 over Bunsen Burner.
06:06 The flask gets heated quickly and undissolved potassium chloride dissolves completely.
06:14 Observe the temperature, as temperature increases potassium chloride dissolves.
06:21 At approximately 40o C, potassium chloride dissolves completely.

Note that grams column shows zero value.

06:33 We can turn off the flame of the Bunsen Burner when not required.
06:39 Click on the Burner. Two black arrows pointing up and down appear.

Click on the down pointing arrow to turn off the Burner.

06:51 Now I will demonstrate the solubility of Cerium(III) Sulphate.
06:56 Note that solubility of Cerium(III) Sulphate is much lower than potassium chloride.
07:04 Transfer 50 mL of Distilled water to graduated cylinder using Precise transfer.

Keep the Distilled water aside.

07:17 Now transfer 50 mL of Distilled water to flask 2 using Precise transfer.

Keep the graduated cylinder aside.

07:28 Drag Weighing boat 2 and place it on the Scale.

Click on TARE.

07:35 We will begin by dissolving just 1 gram of Cerium(III) Sulphate.
07:42 Transfer 1 gram of Cerium(III) Sulphate to Weighing boat 2.
07:48 Keep Cerium(III) Sulphate bottle aside.
07:52 Transfer 1 gram of Cerium(III) Sulphate from Weighing boat 2 to Flask 2.

Keep the Weighing boat aside.

08:03 In the Solution Info panel, observe Species and grams columns.
08:09 Since all the Cerium(III) Sulphate is soluble in water, it indicates zero grams.
08:16 Let us add more Cerium(III) Sulphate to flask 2 to check the solubility.
08:23 Place the Weighing boat 2 back on the Scale. Press TARE.

Weigh 5 grams of Cerium(III) Sulphate.

08:32 Change the transfer bar to Realistic Transfer.
08:36 Drag and place Weighing boat 2 over flask 2.

Click on Pour button gradually.

08:45 Observe the Solution info panel.
08:49 Observe grams column, approximately 3 grams of Cerium(III) Sulphate remains undissolved.
08:58 Let us now check if increase in temperature increases or decreases the solubility.
09:05 Bring the Bunsen Burner close to flask 2.

Place flask 2 over Bunsen Burner.

09:13 Click on the up pointing arrow to turn-on the burner.
09:18 Observe that grams column shows increase in value.

As temperature increases, solubility of Cerium(III)Sulphate decreases.

09:29 Turn-off the Burner.
09:32 For potassium chloride, solubility increases with increase in temperature.
09:38 For Cerium(III)Sulphate, solubility decreases with increase in temperature.
09:44 Click on Problem description window.

We need to check if dissolution of potassium chloride and Cerium (III) Sulphate is endothermic or exothermic.

09:56 Click on Workbench.
09:58 Let us delete Erlenmeyer Flasks from the workbench.
10:03 Click on the flask and press Delete on the keyboard.
10:10 Click on glassware icon.

Select Foam Cup.

10:15 We need two copies of Foam Cups.

Use Duplicate option from the Context menu.

10:24 Rename Foam Cups as 1 and 2.
10:30 Change the Transfer Bar to Precise Transfer.
10:34 Transfer 50 mL of Distilled water to graduated cylinder using Precise transfer.

Keep the Distilled water aside.

10:45 Place Foam cups at a convenient location on the workbench.
10:50 Transfer 50 mL of Distilled water to Foam cup 1 using Precise transfer.
10:58 Click on Foam cup 1.

In the Solution info panel, observe the temperature on the thermometer.

It shows 25o C.

11:10 Foam cups act as Calorimeter for measurements made at constant pressure.
11:17 Heat exchange does not happen easily as it is a better insulator than glass.
11:25 Place the weighing boat 1 on the Scale. Press TARE.
11:31 Weigh 5 grams of potassium chloride.
11:35 Keep potassium chloride bottle aside.
11:39 Bring weighing boat 1 over to Foam cup 1.

Type 5 in the transfer amount input bar.

Click on pour.

11:51 Again click on Foam cup 1.

Observe the temperature, it is now 21o Centigrade.

11:59 Dissolution of potassium chloride in water absorbs heat, hence temperature decreases.
12:07 It is an endothermic process.
12:10 Now let us repeat the same procedure for Cerium(III) Sulphate.
12:15 Fill the graduated cylinder with 50 mL Distilled water.
12:21 Transfer 50 mL of water from graduated cylinder to Foam cup 2.
12:29 Click on Foam cup 2.

Note the temperature of water, it shows 25o Centigrade.

12:38 Place weighing boat 2 on the Scale. Press TARE.
12:43 Weigh 2 grams of Cerium(III) Sulphate.

Keep Cerium(III) Sulphate bottle aside.

12:52 Drag Weighing boat 2 over to Foam cup 2.
12:57 Type 2 in the transfer amount input bar.

Click on Pour.

13:03 Keep the Weighing boat aside.
13:06 Again Click on Foam cup 2.

Observe the temperature, it is now 27.54o Centigrade.

13:17 Dissolution of Cerium(III) Sulphate in water releases heat, hence temperature increases.

It is an exothermic process.

13:28 Let us now analyse the results.

We observed that: For an endothermic process, solubility increases as temperature increases.

13:39 For an exothermic process, solubility decreases as temperature increases.

These observations follow Le Chatelier's principle.

13:50 Let us summarize.

In this tutorial we have Determined the solubilities of potassium Chloride and Cerium(III)sulphate with increase in temperature.

04:02 Observed that solubility of, potassium chloride is Endothermic and

Solubility of Cerium(III)Sulphate is exothermic.

14:13 As an assignment,

List some examples of exothermic and endothermic processes in your daily lives.

14:23 Explain why heat is absorbed or evolved during a reaction.
14:29 Determine whether dissolution of Sodium Chloride is exothermic or endothermic.

(Hint: The problems are under Solubility topic in load homework window)

14:43 The video at the following link summarizes the Spoken Tutorial project.

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15:22 This tutorial is contributed by Snehalatha kaliappan and Madhuri Ganapathi from IIT Bombay.

Thank you for joining.

Contributors and Content Editors

PoojaMoolya