PoojaMoolya: Created page with "{|border =1 |'''Time''' |'''Narration''' |- | 00:01 |Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''. |- |00:07 |In this tutorial we wi..."

2019-01-30T10:42:28Z

Created page with "{|border =1 |'''Time''' |'''Narration''' |- | 00:01 |Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''. |- |00:07 |In this tutorial we wi..."

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

|-
| 00:01
|Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''.

|-
|00:07
|In this tutorial we will learn to standardise:

Strong-Acid with Strong-Base and

Strong-Acid with Weak-Base

using titration method.

|-
|00:18
|To follow this tutorial you should be familiar with- '''ChemCollective Vlabs''' interface.

|-
|00:25
|If not for relevant tutorials, please visit our website.

|-
|00:30
|Here I am using

Mac OS version 10.10.5

|-
|00:35
|ChemCollective Vlabs version 2.1.0

Java version 8.0.

|-
|00:43
|Here I have opened '''Virtual Chemistry labs''' application window.

'''Default lab setup''' window opens.

|-
|00:51
|Let us begin the demonstration with standardization of strong acid with strong base.

|-
|00:59
|We will retrieve required chemicals from '''stockroom'''.

Double-click on '''Strong-acids cabinet'''.

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|01:09
|Now double click to Select, 0.1 Molar Hydrochloric acid from the list.

Close the '''cabinet'''.

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|01:18
|From the '''Strong-bases cabinet''', select, 0.1 Molar sodium hydroxide.

Close the '''cabinet'''.

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|01:26
|From the '''Indicators cabinet''' select '''Phenolphthalein'''.

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|01:30
|Drag the bottle and drop on the '''workbench'''.

Close the '''cabinet'''.

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|01:36
|Click on '''Glassware''' menu.

Now select, '''250 mL Erlenmeyer Flask'''.

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|01:43
|'''10 mL Pipet''' and '''50 mL Buret'''.

Rearrange the apparatus.

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|01:51
|Rename the '''Erlenmeyer Flask''' as A1.

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|01:55
|Using pipet transfer 20 mL of Hydrochloric acid(HCl) into flask A1.

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|02:02
|Place the 10 mL pipet on flask containing Hydrochloric acid(HCl).

|-
|02:08
|In the '''Transfer Amount''' input-bar type 10.

Click on '''Withdraw'''.

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|02:15
|Drag the '''Pipet''' on to flask A1.

|-
|02:19
|In the '''Transfer Amount''' input-bar type 10.

Click on Pour.

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|02:25
|We require 20 mL of HCl for this titration.

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|02:30
|Since we have 10 mL pipet we need to use it twice to transfer 20 mL of Hydrochloric acid(HCl).

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|02:40
|Place '''Phenolphthalein''' bottle over Flask A1.

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|02:44
|Type 0.3 in the '''Transfer Amount''' input bar.

Click on pour.

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|02:51
|Keep '''Phenolphthalein''' bottle and Hydrochloric acid(HCl) aside.

|-
| 02:56
|Drag and place 0.1 Molar Sodium hydroxide(NaOH) over the burete.

|-
|03:02
|Transfer 50 mL of Sodium hydroxide(NaOH) into the buret.

Observe that, burete reading is not zero.

|-
|03:11
|This is because the lower part of the burete is also filled.

Keep Sodium hydroxide(NaOH) flask aside.

|-
|03:19
|Place the burete over Flask A1.

Click on the buret.

|-
|03:25
|Note the initial volume of Sodium hydroxide(NaOH) in the buret from the '''Solution Info''' panel.

|-
|03:32
|Change the '''Transfer Bar''' to '''Realistic Transfer'''.

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

|-
|03:40
|Reaction between Hydrochloric acid(HCl) and Sodium hydroxide(NaOH) is equimolar.

|-
|03:46
|So, end point is expected around 20 mL.

|-
|03:51
|To obtain accurate volume for end-point detection; After adding 19 mL of Sodium hydroxide(NaOH), change the '''Transfer Bar''' to '''Significant Figures Transfer'''.

|-
|04:05
|In the '''Transfer Amount''' input bar type 0.01.

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|04:10
|This will transfer 0.01 mL of Sodium hydroxide(NaOH) for every click on the pour button.

|-
|04:18
|Observe the pH change in the '''Solution Info panel'''.

|-
|04:22
|Click on pour button, observe the faint pink colour in Flask A1.

This is the end-point of titration.

|-
|04:33
|Click on the '''buret'''.

Note the volume of remaining Sodium hydroxide(NaOH) from the solution info panel.

|-
|04:41
|Final calculations are shown on this slide.

|-
|04:45
|We have used the formula M1V1= M2V2 to calculate M1 that is molarity of Hydrochloric acid(HCl).

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|04:54
|We have obtained the value of M1 as 0.1 M.

|-
|04:59
|To clear the workbench, select each component .

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|05:03
|To remove the selected component, click on remove tool.

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|05:07
|Similarly remove all the components from the '''workbench'''.

|-
|05:12
|Let us retrieve solutions for the titration of Strong-acid with Weak-base.

|-
|05:18
|Double-click on '''Strong-acids cabinet''' and select 1 Molar Hydrochloric acid(HCl). .

|-
|05:24
|Now double click on '''Weak-bases cabinet''' and select 1 Molar Ammonia.

|-
|05:33
|For this experiment let us choose '''methyl orange''' as '''indicator'''.

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|05:38
|Drag and place it on the workbench.

|-
|05:42
|Double-click on '''Glassware''' menu.

Select the following glassware;

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|05:48
|'''250 mL Erlenmeyer Flask'''.

'''10 mL Pipet and 50 mL Buret'''.

|-
|05:57
|Rearrange the apparatus.

|-
|06:00
|Rename the Erlenmeyer Flask as A2.

|-
|06:04
|Change the '''Transfer Bar''' to precise transfer.

|-
|06:08
|Using pipet transfer 20 mL of Ammonia into flask A2.

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|06:15
|Place 10 mL pipet on flask containing Ammonia.

|-
| 06:20
|In the '''Transfer Amount''' input-bar type 10.

Click on '''Withdraw'''.

|-
|06:26
|Drag the '''Pipet''' on to flask A2.

|-
| 06:30
|In the '''Transfer Amount''' input-bar type 10.

Click on '''Pour'''.

|-
|06:36
|We need 20 mL of Ammonia, so pipette out twice into flask A2.

|-
|06:50
|Transfer 0.3 mL of '''methyl orange''' into flask A2.

Keep '''methyl orange''' bottle aside.

|-
|07:00
|Drag and place 1 M Hydrochloric acid over the buret.

|-
|07:05
|Transfer 50 mL of Hydrochloric acid into the buret.

|-
|07:13
|Place the buret over flask A2.

|-
|07:17
|Let us start the titration.

|-
|07:20
|Change the '''Transfer Bar''' to '''Realistic Transfer'''.

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

|-
|07:27
|Reaction between Hydrochloric acid(HCl) and ammonia is equimolar.

So, end point is expected around 20 mL.

|-
|07:36
|To obtain accurate volume for end-point detection;

After adding 19 mL of Hydrochloric acid, change the '''Transfer Bar''' to '''Significant Figures Transfer'''.

|-
|07:49
| In the transfer amount input bar type 0.01. Click on '''Pour'''

|-
|07:57
|This will transfer 0.01 mL of Hydrochloric acid(HCl) for every click on pour button.

|-
|08:05
|As we titrate observe the increase in temperature.

|-
|08:09
|Observe the pH changes.

|-
| 08:12
|Transfer a few more drops of Hydrochloric acid(HCl).

Observe the change in colour in Flask A2 to orange colour.

|-
|08:21
|Note the final volume of Hydrochloric acid(HCl) from the Solution info panel.

|-
|08:27
|Your final volume may be different from the value shown here.

|-
|08:32
|Click on '''Spectrometer radio button.

Note the '''Absorbance''' in the '''Solution info panel'''.

|-
|08:40
|Here are the final calculations.

Molarity of ammonia is 1M.

|-
|08:47
|Let us summarize . In this tutorial we have learnt to standardise;

Strong-Acid with Strong-Base and

Strong-Acid with Weak-Base

using titration method.

|-
|09:00
|As an assignment,

Standardize a solution of '''ethanoic acid (acetic acid)''' using titration method.

|-
|09:07
|Hint- All the necessary solutions and apparatus are available in '''default lab setup''' window.

|-
|09:15
|The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

|-
|09:22
|The Spoken Tutorial Project team-

conducts workshops using spoken tutorials and

gives certificates on passing online tests.

For more details, please write to us.

|-
|09:34
|Please post your timed queries on this forum.

|-
|09:39
|Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

|-
| 09:50
|This tutorial is contributed by Snehalatha Kaliappan and Madhuri Ganapathi from IIT-Bombay.

Thank you for joining.
|-
|}

ChemCollective-Virtual-Labs/C2/Acid-base-Titrations/English-timed - Revision history

PoojaMoolya: Created page with "{|border =1 |'''Time''' |'''Narration''' |- | 00:01 |Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''. |- |00:07 |In this tutorial we wi..."