Madhurig at 12:23, 24 March 2017

2017-03-24T12:23:21Z

Madhurig at 12:21, 24 March 2017

2017-03-24T12:21:20Z

Madhurig: Created page with "{|border =1 |'''Time''' |'''Narration''' |- |'''Slide Number 1''' '''Title Slide''' |Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''. |- |'''..."

2017-03-18T14:57:34Z

Created page with "{|border =1 |'''Time''' |'''Narration''' |- |'''Slide Number 1''' '''Title Slide''' |Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''. |- |'''..."

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{|border =1
|'''Time'''
|'''Narration'''
|-
|'''Slide Number 1'''

'''Title Slide'''
|Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''.
|-
|'''Slide Number 2'''

'''Learning Objectives'''
|In this tutorial we will learn to standardise:

Strong-Acid with Strong-Base and

Strong-Acid with Weak-Base

using titration method.
|-
|'''Slide Number 3'''

'''Pre-requisites'''

'''www.spoken-tutorial.org'''.
|To follow this tutorial you should be familiar with-

'''ChemCollective Vlabs''' interface.

If not for relevant tutorials, please visit our website.
|-
|'''Slide Number 4'''

'''System Requirement'''
|Here I am using

Mac OS version 10.10.5

ChemCollective Vlabs version 2.1.0

Java version 8.0
|-
|Point to the window.
|Here I have opened '''Virtual Chemistry labs''' application window.

'''Default lab setup''' window opens.
|-
|Cursor on Workbench.
|Let us begin the demonstration with standardization of-

strong-acid with strong-base.
|-
|Double-click on '''Strong-acids cabinet'''.

Double-click on 0.1M HCl.

Click on '''Cabinet''' icon to close.
|We will retrieve required chemicals from '''stockroom'''.

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

Now double click to Select, 0.1 M Hydrochloric acid from the list.

Close the '''cabinet'''.
|-
|Double-click on '''Strong-bases cabinet'''.

Double-click on 0.1 M NaOH.
|From the '''Strong-bases cabinet''', select, 0.1 M sodium hydroxide.

Close the '''cabinet'''.
|-
|Double-click on '''Indicators cabinet'''.

Click on '''Phenolphthalein''',

drag and drop on the '''workbench'''.
|From the '''Indicators cabinet''' select '''Phenolphthalein'''.

Drag the bottle and drop on the '''workbench'''.

Close the '''cabinet'''.
|-
|Click on '''Glassware''' menu.

Double-click on '''250 mL Erlenmeyer Flask'''.

'''10 mL Pipet''', '''50 mL Buret'''.
|Click on '''Glassware''' menu.

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

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

Rearrange the apparatus.
|-
|Right-click on the flask, from the sub-menu select '''Rename'''.
|Rename the Erlenmeyer Flask as A1.
|-
|Place the '''10 mL Pipet''' on flask containing HCl.

In the '''Transfer Amount''' input-bar type 10.

Click on '''Withdraw'''.

Drag the '''Pipet''' on to flask A1.

In the '''Transfer Amount''' input-bar type 10.

Click on Pour.

Repeat the process again.
|Using pipet transfer 20 mL of HCl into flask A1.

Place the 10 mL pipet on flask containing HCl.

In the '''Transfer Amount''' input-bar type 10.

Click on '''Withdraw'''.

Drag the '''Pipet''' on to flask A1.

In the '''Transfer Amount''' input-bar type 10.

Click on Pour.

We require 20 mL of HCl for this titration.

Since we have 10 mL pipet we need to use it twice to transfer 20 mL of HCl.
|-
|Drag and Place '''Phenolphthalein''' bottle over Flask A1.
|Place '''Phenolphthalein''' bottle over Flask A1.
|-
|Type 0.3 in the '''Transfer Amount''' input bar.

Click on pour.

Drag and keep '''Phenolphthalein''' bottle aside.
|Type 0.3 in the '''Transfer Amount''' input bar.

Click on pour.

Keep '''Phenolphthalein''' bottle and HCl aside.
|-
|Drag and place 0.1M NaOH over the '''buret'''.

Type 50 in the '''Transfer Amount''' input bar.

Click on pour.

Keep NaOH flask aside.

|Drag and place 0.1 M NaOH over the burete.

Transfer 50 mL of NaOH into the buret.

Observe that, burete reading is not zero.

This is because the lower part of the burete is also filled.

Keep NaOH flask aside.
|-
|Drag and place the burete over Flask A1

Point to the '''Solution Info panel'''.
|Place the burete over Flask A1.

Click on the buret.

Note the initial volume of NaOH in the buret from the '''Solution Info''' panel.
|-
|Click on '''Tools''' menu, select '''Realistic Transfer'''.

Click on '''Pour''' button gradually.
|Change the '''Transfer Bar''' to '''Realistic Transfer'''.

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

Reaction between HCl and NaOH is equimolar.

So, end point is expected around 20 mL.
|-
|After adding 19 mL of NaOH, change the transfer mode to '''Significant Figures Transfer'''.

Click on '''Tools''' menu, select '''Transfer Bar'''.

Click on '''Significant Figures Transfer'''.
|To obtain accurate volume for end-point detection;

After adding 19 mL of NaOH, change the '''Transfer Bar''' to '''Significant Figures Transfer'''.
|-
|In the '''Transfer Amount''' input bar type 0.01.

Click on pour.
|In the '''Transfer Amount''' input bar type 0.01.

This will transfer 0.01 mL of NaOH for every click on pour button.

Click on pour.
|-
|Cursor on '''Solution Info panel'''.
|Observe pH change in the '''Solution Info panel'''.
|-
|Click on pour button.

Point to flask A1.
|Click on pour button, observe the faint pink colour in Flask A1.

This is the end-point of titration.
|-
|Click on the '''buret'''.

Point to solution info panel.
|Click on the '''buret'''.

Note the volume of remaining NaOH from the solution info panel.
|-
|'''Slide Number 5'''

'''Calculations'''.

Vi (Initial buret reading of NaOH) = 50 mL

Vf (Final buret reading) = 29.976.

V2 = Vf - Vi = 20.02

M2 (Molarity of HCl) = 0.1 M

V1 (Volume of 0.1M HCl) = 20 mL

M1V1= M2V2

M1x 20 = 0.1 x 20.02

M1 = 0.1 M
|Final calculations are shown on this slide.

We have used the formula M1V1= M2V2
to calculate M1 that is molarity of HCl.

We have obtained the value of M1 as 0.1 M.
|-
|Click on '''Remove''' tool.
|To clear the workbench, select each component .

To remove the selected component, click on remove tool.

Similarly remove all the components from the '''workbench'''.
|-
|Cursor on '''workbench'''.

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

Double-click on 1M HCl.

Double-click on '''Weak-base cabinet'''.

Double-click on 1M Ammonia.

Double-click on '''Indicator cabinet'''.

Double-click on '''methyl orange'''.

Close the '''cabinet'''.
|Let us retrieve solutions for the titration of Strong-acid with Weak-base.

Double-click on '''Strong-acids cabinet''' and select 1 M HCl .

Now double click on '''Weak-bases cabinet''' and select 1M Ammonia.

For this experiment let us choose '''methyl orange''' as '''indicator'''.

Drag and place it on the workbench.
|-
|Double-click on '''Glassware''' menu.

Double-click on '''250 mL Erlenmeyer Flask, 10 mL Pipet, 50 mL Buret'''.
|Double-click on '''Glassware''' menu.

Select the following glassware;

'''250 mL Erlenmeyer Flask'''.

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

Rearrange the apparatus.
|-
|Right-click on the flask, from the sub-menu select '''Rename'''.

In the dialog-box type A2.
|Rename the Erlenmeyer Flask as A2.
|-
|Place the 10 mL pipet on flask containing Ammonia.
|Change the '''Transfer Bar''' to precise transfer.

Using pipet transfer 20 mL of Ammonia into flask A2.

Place 10 mL pipet on flask containing Ammonia.
|-
| In the '''Transfer Amount''' input-bar type 10.

Click on '''Withdraw'''.

Drag the '''Pipet''' on to flask A2.
|In the '''Transfer Amount''' input-bar type 10.

Click on '''Withdraw'''.

Drag the '''Pipet''' on to flask A2.
|-
| In the '''Transfer Amount''' input-bar type 10.

Click on '''Pour'''

Repeat the process again.
|In the '''Transfer Amount''' input-bar type 10.

Click on '''Pour'''.

We need 20 mL of Ammonia, so pipette out twice into flask A2.
|-
|Drag and Place '''methyl orange''' bottle over Flask A2.

Type 0.3 in the '''Transfer Amount''' input bar.

Click on '''pour'''.

Drag and keep '''methyl orange''' bottle aside.
|Transfer 0.3 mL of '''methyl orange''' into flask A2.

Keep '''methyl orange''' bottle aside.
|-
|Drag and place 0.1 M HCl over the buret

Type 50 in the '''Transfer Amount''' input bar. Click on pour.

Keep HCl flask aside.
|Drag and place 1 M HCl over the buret.

Transfer 50 mL of HCl into the buret.
|-
|Drag and place the buret over Flask A2.
|Place the buret over flask A2.
|-
|Cursor on workbench.
|Let us start the titration.
|-
|Click on '''Tools''' menu, select '''Realistic Transfer'''.

Click on '''Pour''' button gradually.
|Change the '''Transfer Bar''' to '''Realistic Transfer'''.

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

Reaction between HCl and ammonia is equimolar.

So, end point is expected around 20 mL.
|-
|After adding 19 mL of HCl,

Click on '''Tools''' menu, select '''Transfer Bar'''.

Click on '''Significant Figures Transfer'''.
|To obtain accurate volume for end-point detection;

After adding 19 mL of HCL, change the '''Transfer Bar''' to '''Significant Figures Transfer'''.
|-
|In the '''Transfer Amount''' input bar type 0.01.

Click on '''Pour'''.

In the '''Transfer Amount''' input bar type 0.01

click on pour.
|This will transfer 0.01 mL of HCl for every click on pour button.

As we titrate observe the increase in temperature.
|-
|Cursor on '''Solution Info panel'''.
|Observe the pH change.
|-
|In the '''Transfer Amount''' input bar type 0.01.

Click on Pour.

Cursor on '''Solution Info panel'''.

|Transfer a few more drops of HCl.

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

Note the final volume of HCl from the Solution info panel.

Your final volume may be different from the value shown here.
|-
|Click on '''Spectrometer''' radio button.

Point to the '''Absorbance''' in the '''Solution info panel'''.
|Click on '''Spectrometer radio button.

Note the '''Absorbance''' in the '''Solution info panel'''.
|-
|'''Slide Number 6'''

'''Calculations'''

Vi (Initial buret reading of HCl) = 50 mL

Vf (Final buret reading) = 29.997.

V2 = Vf - Vi = 20.00

M2 (Molarity of HCl) = 1 M

V1 (Volume of NaOH) = 20 mL

M1V1= M2V2

M1 x 20 = 1 x 20.00

M1 = 1 M
|Here are the final calculations.

Molarity of ammonia is 1M.
|-
|'''Slide Number 7'''

'''Summary '''
|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.
|-
|'''Slide Number 8'''

'''Assignment'''
|As an assignment,

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

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

|-
|'''Slide Number 9''':

'''About Spoken Tutorial project'''
|The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.
|-
|'''Slide Number 10''':

'''Spoken Tutorial workshops'''
|The Spoken Tutorial Project team:

conducts workshops using spoken tutorials and

gives certificates on passing online tests.

For more details, please write to us.
|-
|'''Slide Number 11''':

'''Forum for specific questions''':

Do you have questions in THIS Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question

Explain your question briefly

Someone from our team will answer them.
|Please post your timed queries on this forum.
|-
|'''Slide Number 12''':

'''Acknowledgement'''
|Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at
this link.
|-
|
|This tutorial is contributed by Snehalatha Kaliappan and Madhuri Ganapathi from IIT-Bombay.

Thank you for joining.
|-
|}

@@ Line 225: / Line 225: @@
 Vf (Final buret reading) =  29.991 mL
-V2 = Vf - Vi = 20.009 mL
+V2 = Vi - Vf = 20.009 mL
 M2 (Molarity of NaOH) = 0.1 M
@@ Line 415: / Line 415: @@
 M2 (Molarity of HCl) = 1 M
-V1 (Volume of NH 3) = 20 mL
+V1 (Volume of NH3) = 20 mL
 M1V1= M2V2

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

Madhurig at 12:23, 24 March 2017

Madhurig at 12:21, 24 March 2017

Madhurig: Created page with "{|border =1 |'''Time''' |'''Narration''' |- |'''Slide Number 1''' '''Title Slide''' |Welcome to this spoken tutorial on '''Acid-Base Titrations''' using '''Vlabs'''. |- |'''..."