PoojaMoolya: Created page with " {| border =1 |'''Time''' |''' Narration''' |- | 00:01 | Welcome to this spoken tutorial '''Heat of Reaction ''' using ''' Vlabs'''. |- | 00:06 | In this tutorial, we..."

2019-01-30T10:33:11Z

Created page with " {| border =1 |'''Time''' |''' Narration''' |- | 00:01 | Welcome to this spoken tutorial '''Heat of Reaction ''' using ''' Vlabs'''. |- | 00:06 | In this tutorial, we..."

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{| border =1
|'''Time'''
|''' Narration'''

|-
| 00:01
| Welcome to this spoken tutorial '''Heat of Reaction ''' using ''' Vlabs'''.

|-
| 00:06
| In this tutorial, we will learn to, Determine heat change for the neutralisation of Sodium hydroxide (NaOH) and Hydrochloric acid(HCl).

|-
| 00:16
| Calculate heat of reaction for three different reactions.

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| 00:21
| The three reactions are shown here.

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| 00:25
| To follow this tutorial you should be familiar with, '''ChemCollective Vlabs''' interface.

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| 00:32
| If not, for relevant tutorials please visit our website.

|-
| 00:38
| Here, I am using Mac OS 10.10.5

|-
| 00:44
| ChemCollective Vlabs version 2.1.0

Java version 8.

|-
| 00:52
| I have opened a '''Virtual Chemistry lab''' application window.

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|00:57
| Click on '''File''' and select ''' Load homework ''' option.

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| 01:03
| '''Default Lab setup ''' dialog box opens.

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| 01:08
| In the box, select '''Thermochemistry'''.

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| 01:12
| Double click on '''Heats of the reaction- Hess’s Law''' option.

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| 01:17
| Click on '''Problem Description''' in '''Stockroom Explorer'''.

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| 01:22
| The '''Problem Description'''here states that, we have to determine and compare '''heat of reaction''' for 3 different reactions.

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| 01:31
| Scroll down the page and read, '''Procedure''', '''Processing the data''', '''Discussion''' and '''Conclusion'''

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| 01:42
| This experiment is an illustration of '''Hess's law'''.

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| 01:46
| Which states that , total heat change during the complete course of a reaction is same,

whether the reaction is made in one step or in several steps.

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| 01:59
| '''Heat of reaction''' is also known as '''Standard enthalpy''' change.

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| 02:04
| '''delta rH = delta r H 1 + delta r H 2 + delta r H 3''' ,etc.

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| 02:13
| Sum of Heats of reactions for, Reaction 1 and Reaction 3 must be equal to heat of reaction for Reaction 2.

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| 02:22
| Let us go back to '''Workbench'''.

We will begin the first reaction.

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|02:28
| Let us select the required chemicals and apparatus for the reaction.

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|02:34
| From the '''Chemical Stockroom''', Double-click on '''Distilled water'''.

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| 02:39
| Click on '''Solids''' cabinet and double-click on '''Sodium hydroxide'''.

Close the '''cabinet'''.

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| 02:47
| From the glassware menu, we will select a 50 mL '''Graduated Cylinder''' and a '''Foam Cup'''.

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| 02:56
| From the instrument menu, select '''Weighing Boat ''' and a ''' Scale'''.

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|03:02
| Transfer 50 mL of '''Distilled water ''' to the '''Graduated Cylinder'''.

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|03:08
| In the '''Transfer amount ''' input bar, type 50 and click on '''Pour'''.

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| 03:15
| Weigh 1 gram of''' Sodium hydroxide''' using '''Weighing Boat'''.

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|03:21
| Place the '''Weighing Boat''' on the '''Scale''', click on '''TARE'''.

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|03:27
| Drag the '''Sodium hydroxide''' bottle over the '''weighing boat'''.

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|03:32
| Type 1 in the '''Transfer amount input bar''' and click on '''Pour '''.

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|03:39
| Transfer '''Sodium hydroxide''' from '''Weighing Boat''' to '''Foam Cup'''.

Click on '''Pour'''.

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| 03:47
| Click on '''Foam Cup'''.

In the '''Solution info panel''', Click on '''Solid''' radio button and observe the weight in '''grams''' column.

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| 03:58
| Click on the '''Graduated Cylinder''' and record its temperature.

'''Thermometer''' shows the temperature as 25 degrees '''Celsius'''.

|-
|04:08
| Drag the '''Graduated Cylinder''' over to the '''Foam Cup'''.

Type 50 in the '''Transfer Amount''' input bar and click on '''Pour'''.

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| 04:21
| Click on '''Foam Cup'''.

Record the highest temperature on the '''thermometer'''.

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|04:27
| '''Thermometer''' shows 30.29 degrees '''Celsius'''.

|-
|04:32
|Observe the '''grams ''' column, it shows zero.

This is because all the '''Sodium hydroxide''' has now dissolved in water.

|-
| 04:42
| Lets see how to calculate heat of the reaction.

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| 04:46
| '''Heat of reaction (q)''' is calculated using the formula.

'''q = m * s * ∆T'''

wherein 'm' is mass of the reactants

|-
|04:57
| 's' is the specific heat of the product and

'∆T' is the change in temperature in the reaction.

|-
| 05:05
| Heat energy calculation for this reaction is given here.

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| 05:11
| Calculation of '''Molar Heat energy '''(delta H) in Kilo Joules per mol is given here.

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|05:18
| delta H for reaction 1 '''Sodium hydroxide''' is -45.32 Kilo Joules per mol

|-
| 05:26
| Lets go back to '''workbench'''.

Let us delete the used '''Graduated Cylinder''' and '''Foam Cup'''.

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| 05:34
| We will now move on to demonstrate second exothermic reaction.

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|05:40
| From '''Glassware '''menu, Take a new 50 mL '''Graduated Cylinder''' and a '''Foam Cup'''.

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| 05:49
| From the '''Chemical Stockroom''', select '''Strong-acids cabinet'''.

Double click to get '''0.5 M Hydrochloric acid'''.

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|05:59
| Close the '''Cabinet'''.

|-
| 06:01
| Transfer 50 mL of '''Hydrochloric acid''' into the '''Graduated Cylinder'''.

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|06:08
| Weigh 1 gram of '''Sodium hydroxide''' using '''Weighing Boat'''.

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|06:15
| Transfer '''Sodium hydroxide''' from '''Weighing Boat''' to '''Foam Cup'''.

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| 06:21
| Click on the '''Graduated Cylinder''', record its temperature.

|-
|06:27
| Pour the contents of the '''Graduated Cylinder''' into the '''Foam Cup.'''

|-
| 06:33
| Click on the '''Foam Cup'''.

Record the highest temperature on the thermometer.

|-
|06:39
| '''Thermometer''' shows 36.96 degree Celcius.

|-
|06:45
| Calculation of Molar Heat energy (delta H) in Kilo Joules per mol is given here.

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|06:51
| delta H for Reaction 2 is -102.47 Kilo Joules per mol

|-
|07:00
|Delete the used apparatus and chemicals from the '''Workbench'''.

|-
|07:06
| From '''Glassware''' menu take a new 25 mL '''Graduated Cylinder''' and a '''Foam Cup '''

|-
| 07:14
| We need two '''Graduated Cylinders'''.

Use '''Duplicate''' option in the context menu to make the copies.

|-
|07:22
|Drag both the '''cylinders''' to a convenient place on the '''Workbench'''.

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| 07:27
| Label the cylinders as '''A''' and '''B'''.

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| 07:35
| From the '''Chemical Stockroom''' click on '''Strong-acids cabinet'''.

Double click on '''1.0 M Hydrochloric acid'''.

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| 07:44
| Close the '''cabinet'''.

From the '''Strong-bases cabinet''', double click on 1.0 M '''Sodium hydroxide'''.

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| 07:52
| Close the '''cabinet'''.

|-
|07:54
| Transfer 25 mL of '''Hydrochloric acid(HCl)''' into '''graduated cylinder A'''.

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| 08:01
| Pour the '''Hydrochloric acid(HCl)''' from '''graduated cylinder''' to '''Foam Cup'''.

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| 08:07
| Note the temperature on the '''thermometer'''.

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| 08:11
| Measure 25 mL of '''Sodium hydroxide''' in '''Graduated Cylinder B'''.

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| 08:18
| Pour the measured '''Sodium hydroxide''' into the '''Foam Cup'''.

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| 08:24
| Click on '''Foam Cup'''.

Allow the reaction to take place for a few seconds.

|-
| 08:31
| Record the highest temperature. '''Thermometer''' shows 31.67 degree Celcius.

|-
|08:40
| Calculation of '''Molar Heat energy''' for reaction three is given here.

delta H for reaction 3( Rx3) is -56.03 Kilo Joules per mol

|-
| 08:53
| Now, Let us now analyze the results.

The value of Sum of heats of reactions for Reaction 1 and Reaction 3 is -101.35 Kilo Joules per mol

|-
| 09:07
| The value of heat of reaction for Reaction 2 is -102.47 Kilo Joules per mol.

Therefore this experiment illustrates '''Hess's law'''.

|-
| 09:21
| Let us summarize.

|-
| 09:23
| In this tutorial we have, Determined heat change for neutralization of '''Sodium hydroxide'''

and '''Hydrochloric acid'''.

|-
| 09:32
| Calculated heat of reaction for 3 different reactions.

|-
| 09:37
| For the assignment, Explain why the reactions are exothermic.

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| 09:42
| Repeat Reaction 1 using 4 grams of '''Sodium hydroxide''' and calculate the heat of reaction.

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| 09:51
| Compare its value with the reaction in which 1 gram of '''Sodium hydroxide''' was used.

|-
| 09:58
| The video at the following link summarizes the '''Spoken Tutorial project'''.

Please download and watch it.

|-
| 10:06
| The '''Spoken Tutorial Project''' team: conducts workshops using spoken tutorials and

gives certificates on passing online tests.

For more details, please write to us.

|-
| 10:18
| Please post your timed queries in this forum.

|-
| 10:22
| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

|-
| 10:34
| This tutorial is contributed by Snehalatha kaliappan and Madhuri Ganapathi from IIT Bombay.

Thank you for joining.

|-
|}

ChemCollective-Virtual-Labs/C3/Heat-of-Reaction/English-timed - Revision history

PoojaMoolya: Created page with " {| border =1 |'''Time''' |''' Narration''' |- | 00:01 | Welcome to this spoken tutorial '''Heat of Reaction ''' using ''' Vlabs'''. |- | 00:06 | In this tutorial, we..."