ChemCollective-Virtual-Labs/C2/Effect-of-temperature-on-solubility/English-timed
| 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.
Please download and watch it. |
| 14:52 | The Spoken Tutorial Project team: conducts workshops using spoken tutorials and
gives certificates on passing online tests. For more details, please write to us. |
| 15:05 | Please post your timed queries in this forum. |
| 15:10 | Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
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| 15:22 | This tutorial is contributed by Snehalatha kaliappan and Madhuri Ganapathi from IIT Bombay.
Thank you for joining. |
