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

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||'''Time''' 
||'''Narration''' 

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|00:01
||Hello everyone. 

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

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||00:10
|| In this tutorial, we will learn 
     
About solubility of salts with temperature. 

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||00:16
||Check if solubility is exothermic or endothermic. 

Study the relationship between solubility and heat transfer. 

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

'''ChemCollective Vlabs''' interface. 

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||00:33
||If not for relevant tutorials please visit our website. 

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||00:39
||Here I am using 

Mac OS  version 10.10.5 

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||00:45
||ChemCollective Vlabs version 2.1.0 

Java version 8 

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||00:53
||Here I have opened a '''virtual chemistry lab''' application window. 

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||00:58
||Go to '''File'''->'''Load homework''' option. 

Select '''Solubility and Solids'''. 

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||01:06
||Click on '''Temperature and solubility of salts''' option. 

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||01:11
||Click on problem description in the stockroom explorer. 

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||01:16
||Please pause the video here and read the problem description. 

Resume the video once you finish reading. 

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||01:25
||The problem has 3 sections. 

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

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||01:36
||In Second section: Observe whether dissolution of '''Potassium chloride''' and '''Cerium sulphate''' is exothermic or endothermic. 

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||01:46
||In the Third section: we have to explain the observations in section 1 and 2 based on a chemical principle. 

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||01:55
||Click on '''Workbench'''. 

Let us select required chemicals and apparatus for this experiment. 

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||02:04
||From the '''Stockroom explorer''', Click on '''Potassium chloride, Cerius sulfate''' and '''Distilled water''' icons. 

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||02:12
||Click on '''glassware''' icon. 

Select 50 mL '''Graduated Cylinder'''. 

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||02:19
||Again click on '''glassware''' icon. 

Select 250 mL '''Erlenmeyer Flask'''. 

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||02:27
||We need two copies of 250 mL '''Erlenmeyer Flasks'''. 

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||02:33
||Use '''Duplicate''' option from the '''context menu''' to make the copies. 

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||02:38
||Click on '''select tools''' icon. 

Select '''Scale''' and '''Weighing boat'''. 

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||02:48
||We need two copies of '''Weighing boats'''. 

Again use '''Duplicate''' option from the '''context menu'''. 

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

Similarly rename the '''Weighing boats''' as 1 and 2. 

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||03:13
||Now place each set of apparatus separately on the '''workbench'''. 

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||03:18
||Drag the '''Distilled water''' tank over to '''graduated cylinder'''. 

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||03:23
||In the '''Transfer amount input bar''', type 50. 

Click on '''Pour'''. 

Keep the '''Distilled water''' aside. 

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||03:33
||Transfer 50 mL of '''Distilled water''' to flask 1 using '''Precise Transfer'''. 

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||03:43
||Keep the '''graduated cylinder''' aside. 

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||03:46
||Drag the '''weighing boat 1''' and place it on the '''scale'''. 

Click on '''TARE'''. 

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||03:52
||Drag the '''Potassium chloride''' bottle over to '''weighing boat 1'''. 

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||03:57
||Type 5 in the '''transfer amount input bar'''. Click on '''Pour'''. 

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||04:03
||Keep '''Potassium chloride''' bottle aside. 

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||04:07
||Drag the '''weighing boat 1''' and place it on  '''Flask 1'''. 

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||04:12
||In the '''transfer amount input bar''',  Type 5. 

Click on '''pour'''. 

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||04:18
||Keep the '''weighing boat''' aside. 

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|| 04:21
||In the '''Solution Info Panel''', click on '''Solid''' radio button. 

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||04:26
||Observe, '''Species''' and '''grams''' columns. 

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||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. 

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||04:41
||This indicates that '''potassium chloride''' is readily soluble in water. 

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||04:47
||Let us keep on adding '''Potassium chloride''' to flask 1 until undissolved '''Potassium chloride''' remains in '''flask 1'''. 

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||04:57
||Place the '''weighing boat 1''' back on the '''Scale'''. Click on '''TARE'''. 

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||05:03
||Drag and place '''Potassium chloride''' bottle over  '''weighing boat 1''' 

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||05:09
||Type 15 in the '''transfer amount input bar'''. Click on '''pour'''. 

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||05:15
||Keep '''Potassium chloride''' bottle aside. 

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||05:19
||Change the '''Transfer Bar''' to '''Realistic Transfer''' using '''Tools''' menu. 

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||05:25
||Drag and place '''weighing boat 1''' over '''flask 1'''. 

Click on '''Pour''' button gradually. 

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||05:33
||Observe the '''Solution info panel'''. 

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||05:37
||Observe '''grams''' column, approximately 2 grams of '''Potassium chloride''' remains undissolved. 

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||05:45
||Let us now check if increase in temperature increases or decreases the solubility. 

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||05:52
||Click on '''Select tool''' icon, choose '''Bunsen Burner'''. 

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||05:58
||Bring the '''Bunsen Burner''' close to '''flask 1'''. 

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||06:02
||Place '''flask 1''' over '''Bunsen Burner'''. 

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||06:06
||The flask gets heated quickly and undissolved '''potassium chloride''' dissolves completely. 

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||06:14
||Observe the temperature, as temperature increases '''potassium chloride''' dissolves. 

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||06:21
||At approximately 40<sup>o</sup> C, '''potassium chloride''' dissolves completely.  

Note that '''grams''' column shows zero value. 

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||06:33
||We can turn off the flame of the '''Bunsen Burner''' when not required. 

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||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'''. 

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||06:51
||Now I will demonstrate the solubility of '''Cerium(III) Sulphate'''. 

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||06:56
||Note that solubility of '''Cerium(III) Sulphate''' is much lower than '''potassium chloride'''. 

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||07:04
||Transfer 50 mL of '''Distilled water''' to '''graduated cylinder'''  using '''Precise transfer'''. 

Keep the '''Distilled water''' aside. 

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

Keep the '''graduated cylinder''' aside. 

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

Click on '''TARE'''. 

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||07:35
||We will begin by dissolving just 1 gram of  '''Cerium(III) Sulphate'''. 

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||07:42
||Transfer 1 gram of '''Cerium(III) Sulphate''' to '''Weighing boat 2'''. 

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||07:48
||Keep '''Cerium(III) Sulphate''' bottle aside. 

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||07:52
||Transfer 1 gram of '''Cerium(III) Sulphate''' from '''Weighing boat 2''' to '''Flask 2'''. 

Keep the '''Weighing boat''' aside. 

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||08:03
||In the '''Solution Info panel''', observe '''Species''' and '''grams''' columns. 

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||08:09
||Since all the Cerium(III) Sulphate''' is soluble in water, it indicates zero grams. 

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||08:16
||Let us add more '''Cerium(III) Sulphate''' to '''flask 2''' to check the solubility. 

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||08:23
||Place the '''Weighing boat 2''' back on the '''Scale'''. Press '''TARE'''. 

Weigh 5 grams of  '''Cerium(III) Sulphate'''. 

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||08:32
||Change the '''transfer bar''' to '''Realistic Transfer'''. 

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||08:36
||Drag and place '''Weighing boat 2''' over '''flask 2'''. 

Click on '''Pour''' button gradually. 

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||08:45
||Observe the '''Solution info panel'''. 

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||08:49
||Observe '''grams''' column, approximately 3 grams of '''Cerium(III) Sulphate''' remains undissolved. 

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||08:58
||Let us now check if increase in temperature increases or decreases the solubility. 

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||09:05
||Bring the '''Bunsen Burner''' close to '''flask 2'''. 

Place flask 2 over '''Bunsen Burner'''. 

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||09:13
||Click on the up pointing arrow to turn-on the '''burner'''. 

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||09:18
||Observe that  '''grams''' column shows increase in value.  

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

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||09:29
||Turn-off the '''Burner'''. 

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||09:32
||For '''potassium chloride''', solubility increases with increase in temperature. 

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||09:38
||For '''Cerium(III)Sulphate''', solubility decreases with increase in temperature. 

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||09:44
||Click on '''Problem description''' window. 

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

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||09:56
||Click on '''Workbench'''. 

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||09:58
||Let us delete '''Erlenmeyer Flasks''' from the '''workbench'''. 

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||10:03
||Click on the flask and press '''Delete''' on the keyboard. 

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||10:10
||Click on '''glassware''' icon. 

Select '''Foam Cup'''. 

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||10:15
||We need two copies of '''Foam Cups'''. 

Use '''Duplicate''' option from the '''Context menu'''. 

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||10:24
||Rename '''Foam Cups''' as 1 and 2. 

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||10:30
||Change the '''Transfer Bar''' to '''Precise Transfer'''. 
 
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||10:34
||Transfer 50 mL of '''Distilled water''' to '''graduated cylinder'''  using '''Precise transfer'''. 

Keep the '''Distilled water''' aside. 

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||10:45
||Place '''Foam cups'''  at a convenient location on the '''workbench'''. 

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||10:50
||Transfer 50 mL of '''Distilled water''' to '''Foam cup 1''' using '''Precise transfer'''. 

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||10:58
||Click on '''Foam cup 1'''. 

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

It shows 25<sup>o</sup> C. 

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||11:10
||'''Foam cups act as '''Calorimeter''' for measurements made at constant pressure. 

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||11:17
||Heat exchange does not happen easily as it is a better insulator than glass. 

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||11:25
||Place the '''weighing boat 1''' on the '''Scale'''. Press '''TARE'''. 

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||Weigh 5 grams of '''potassium chloride'''. 
 
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||11:35
||Keep '''potassium chloride''' bottle aside. 

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||Bring '''weighing boat 1''' over to '''Foam cup 1'''. 

Type 5 in the '''transfer amount input bar'''. 

Click on '''pour'''. 

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||11:51
||Again click on '''Foam cup 1'''. 

Observe the temperature, it is now 21<sup>o</sup> Centigrade. 

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||11:59
||Dissolution of '''potassium chloride''' in water absorbs heat, hence temperature decreases. 

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||12:07
||It is an endothermic process. 

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||12:10
||Now let us repeat the same procedure for '''Cerium(III) Sulphate'''. 

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|| 12:15
||Fill the '''graduated cylinder''' with  50 mL '''Distilled water'''. 

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||12:21
||Transfer 50 mL of water from '''graduated cylinder''' to '''Foam cup 2'''. 

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||12:29
||Click on '''Foam cup 2'''. 

Note the temperature of water, it shows 25<sup>o</sup> Centigrade. 

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||12:38
||Place '''weighing boat 2''' on the '''Scale'''. Press '''TARE'''. 

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||12:43
||Weigh 2 grams of  '''Cerium(III) Sulphate'''. 

Keep '''Cerium(III) Sulphate''' bottle aside. 

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||12:52
||Drag '''Weighing boat 2''' over to '''Foam cup 2'''. 

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||12:57
||Type 2 in the '''transfer amount input bar'''. 

Click on '''Pour'''. 

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||13:03
||Keep the '''Weighing boat''' aside. 

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||13:06
||Again Click on '''Foam cup 2'''. 

Observe the temperature, it is now 27.54<sup>o</sup> Centigrade. 

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

It is an exothermic process. 

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|| 13:28
||Let us now analyse the results. 

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

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

These observations follow  '''Le Chatelier's principle'''.    

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||13:50
||Let us summarize. 
 
In this tutorial we have Determined the solubilities of potassium Chloride and Cerium(III)sulphate  with increase in temperature. 

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

Solubility of Cerium(III)Sulphate is exothermic. 

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||14:13
||As an assignment, 

List some examples of exothermic and endothermic processes in your daily lives. 
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||14:23
||Explain why heat is absorbed or evolved during a reaction. 

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||14:29
||Determine whether dissolution of '''Sodium Chloride''' is exothermic or endothermic. 

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

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

Please download and watch it. 

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||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. 

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||15:05
||Please post your timed queries in this forum. 

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||15:10
||Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. 

More information on this mission is available at this link. 

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|| 15:22
||This tutorial is contributed by Snehalatha kaliappan and Madhuri Ganapathi from IIT Bombay. 
 
Thank you for joining. 
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