View source for PhET-Simulations-for-Chemistry/C2/pH-Scale/English

{| border =1
||'''Visual Cue'''
||'''Narration'''
|- 
|| '''Slide Number 1'''

'''Title slide'''
|| Welcome to this Spoken tutorial on '''pH scale''' using interactive '''PhET simulation'''.
|-
|| '''Slide Number 2'''

'''Learning Objectives'''
|| In this tutorial we will learn-

How to use interactive '''PhET simulation''', '''pH scale'''.
|-
|| '''Slide Number 3'''

'''Pre-requisites'''
|| To follow this tutorial, 

Learners should be familiar with topics in high school science.
|-
|| '''Slide Number 4'''

'''System Requirements'''
|| Here I am using-

Ubuntu Linux OS version 14.04

Java version 1.7.0

Firefox Web Browser version 53.02.2.
|-
|| '''Slide Number 5'''

'''Learning Goals'''
|| Using this '''simulation''' we will learn to-

1.Determine whether a given solution is an acid or a base.

2.Arrange acids and bases according to their strength.

3.Determine the concentration of hydroxide ion, hydronium ion and water at a given '''pH'''.
|-
|| '''Slide Number 6'''

'''Learning Goals'''
|| Using this '''simulation''' we will learn about,

4. '''pH''' of a solution.

5. Effect of dilution on '''pH''' of a solution.

6. '''Logarithmic''' and '''Linear''' scale.
|-
|| '''Slide Number 7'''

'''pH scale'''
|| '''pH scale''' is a, numeric scale used to specify the acidity or basicity of an aqueous solution.

'''pH''' is a measure of hydrogen ion concentration in '''mol/L'''.
|-
|| '''Slide Number 8'''

'''Formula for pH calculation'''.

Point to the formula.

'''pH = - log[H<sup>+</sup>]'''

|| '''pH''' is negative logarithm to base 10 of hydrogen ion concentration.

'''pH = - log[H<sup>+</sup>]'''
|-
|| '''Slide Number 9'''

'''pH for Acids, Bases and Neutral Solutions'''.

|| For acidic solutions, '''pH''' is less than 7(< 7).

For basic solutions, '''pH''' is greater than 7 (> 7).

For neutral solutions, '''pH''' is equal to 7 (= 7).
|-
|| '''Slide Number 10'''

'''Link for PhET simulation'''

point to 

[http://phet.colorado.edu/ http://phet.colorado.edu]
|| Use the given link to download the '''simulation'''.

[http://phet.colorado.edu/ http://phet.colorado.edu]
|-
|| Point to the file in '''Downloads''' folder.
|| I have already downloaded the '''pH Scale PhET''', to my '''Downloads''' folder.
|-
|| Right click on '''ph-scale html file'''.

Click on '''Open With Firefox Web Browser'''.
|| To open the '''simulation''', right click on '''ph-scale html file'''.

Choose the option '''Open With Firefox Web Browser'''.

The file opens in the browser.
|-
|| Cursor on the '''interface'''.
|| This is the interface of '''pH scale simulation'''.
|-
|| Point to the each screen.
|| The interface has three screens-

'''Macro''' 

'''Micro'''

'''My solution'''
|-
|| Cursor on the '''Macro''' screen.

Click on '''Macro '''screen. 
|| Let us begin our '''simulation''' with '''Macro''' screen.

Click on '''Macro''' screen to open it.
|-
|| Cursor on '''Macro''' screen.

Cursor on a '''pH scale'''.

Point to a green '''probe'''.

Point to a '''pH meter'''.

|| This screen has-

A '''pH scale''' on the left, to display '''pH''' range from 0 to 14.

A green '''probe''' attached to '''pH scale''' to measure '''pH''' and 

A '''pH meter''' to show '''pH''' of the liquids.
|-
|| Cursor on '''water pump'''.

Cursor on '''water container'''.

Point to '''pump'''.
|| A water pump on the right side of screen to add water.

A graduated water container filled by default with '''Chicken Soup'''.

A pump to remove solution is attached at the bottom left of the container.
|-
|| Point to the dropper.

Cursor on drop down box.


Point to '''Chicken Soup.'''
|| A dropper to add liquid.

A drop down box to choose one of the liquids.

By default '''Chicken Soup''' is selected.
|-
|| Point to '''Reset button'''.
|| A '''Reset''' button is provided at the right hand side bottom corner.
|-
|| Click on the drop down arrow.

Scroll to '''Battery Acid''' and click.

Point to the container.

Point to 0.5 L.
|| Click on the drop down arrow.

Scroll to '''Battery Acid ''' and click on it.

Notice that, the container is filled with '''Battery Acid''' up to 0.50 L (0.5litres).
|-
|| Drag the green '''probe'''.

Point to the '''pH meter'''.

|| Drag the green '''probe''' into the container and observe the '''pH'''.

'''Meter''' shows the '''pH''' value as 1.0.

As '''pH''' is less than 7(<7), '''Battery Acid''' is an acidic solution.
|-
|| Click on water pump.

Point to the container.


Cursor on the '''pH meter'''.
|| Now click on the water pump to add more water.

Increase the water level up to 1Litre.

Observe the change in '''pH''' on addition of water.

Now '''pH meter''' shows '''pH''' value as 1.30.
|-
|| Point to '''pH meter'''.
|| Notice that '''pH''' of '''Battery Acid''' increases on addition of water.

This is because hydrogen [H<sup>+</sup>] ion concentration decreases with dilution.
|-
|| 
|| Now we will select another solution.
|-
|| Click on drop down arrow.

Scroll and click on '''Hand Soap'''.

Point to the container.
|| Click on drop down arrow.

Scroll to '''Hand Soap''' and click on it.

Container is filled with '''Hand Soap''' solution.
|-
|| Point to the '''pH meter'''.

|| Here, '''pH meter''' shows the value of '''pH''' as 10.00.

This indicates that '''Hand Soap''' is basic in nature.
|-
|| Click on water pump.

|| Click on water pump to add water to '''Hand Soap''' solution.
|-
|| Click on water pump.

Cursor on the '''pH meter'''.
|| For 1 L, '''Hand Soap''' solution shows a '''pH''' value of 9.70.

We can see that '''pH''' of '''Hand Soap''' solution decreases on dilution.

This is because hydroxide ion (OH<sup>-</sup> ) concentration decreases with dilution.
|-
|| Click on bottom pump.


Click on dropper.


Point to the '''pH meter'''.
|| Click on the bottom pump to remove half litre of '''Hand Soap''' solution.

Click on the dropper and increase the level of '''Hand Soap''' solution to 0.6 L.

Notice the change in '''pH'''.

It increases as concentration of hydroxide ion (OH<sup>-</sup> ) increases. 
|-
|| 
|| Now we will arrange the acids and bases according to their strengths.
|-
|| Click on drop down arrow.

Click on '''Blood'''.

Point to the container and 0.5 L.


Point to the '''pH meter'''.
|| For that we will check the '''pH''' of different liquids.

Click on drop down arrow and select '''Blood'''.

Container is filled with '''Blood''' up to 0.50 L.

'''Meter''' shows the '''pH''' value as 7.40.

As '''pH''' is greater than 7( >7), '''Blood''' is a basic solution.
|-
|| Click on drop down arrow.

Click on '''Orange Juice'''.

Point to the '''pH meter''' and 0.50 L.
|| Again click on drop down arrow and select '''Orange Juice'''.

'''Meter''' shows '''pH''' value as 3.50 for 0.50 L.

It is clear that '''Orange Juice''' is an acidic solution.
|-
|| '''Slide Number 11'''

pH of '''acids''' and '''bases'''.
|| According to the above '''pH''' values the order is as follows. 

'''Hand soap''' > '''Blood''' > '''Orange Juice''' > '''Battery Acid'''.
|-
|| '''Slide Number 12'''

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

Check the '''pH''' of each liquid.

And arrange the liquids according to the '''pH''' range.
|-
|| Point to the '''Micro''' screen.

Click on the '''Micro''' screen.
|| Now, we will move on to '''Micro''' screen.

Click on '''Micro''' screen at the bottom of the interface.
|-
|| Cursor on the screen.

Point to '''pH scale'''.

Point to '''Concentration''' and '''Quantity''' switch.

Point to and click on -ve red button.

Point to '''Logarithmic''' and '''Linear''' switch.

|| This screen has the following tools-

A '''pH scale''' on the left hand side of screen.

A switch on the top of '''pH scale''' to select between '''Concentration''' and '''Quantity'''.

A red button with a minus(-) to hide '''pH scale'''.

A switch at the bottom to select between '''Logarithmic''' and '''Linear scale'''.
|-
|| Point to Check boxes.


Point to and click on -ve red button.
|| Check boxes to select-

Hydronium ion to hydroxide ion ratio '''(H<sub>3</sub>0<sup>+</sup>/OH<sup>-</sup> )''' and  '''Molecule count'''.

In the '''pH meter''', a red button with a minus(-) to hide '''pH reader''' and value.
|-
|| Click on drop down arrow.

Scroll and click on '''Soda Pop'''.

Point to the container.
|| Click on the drop down arrow and select '''Soda Pop'''.

Container is filled with '''Soda Pop'''.
|-
|| Point to '''pH meter'''. 
|| '''pH meter''' shows '''pH''' value as 2.50.

It means, '''Soda Pop''' is an acidic solution.
|-
|| Point to '''pH scale''' 3.2 x 10<sup>-3</sup>.

Point to '''pH scale''' 3.2 x 10<sup>-12</sup>.
|| As '''Soda Pop''' is acidic,

concentration of hydronium ion is high and hydroxide ion<sup> </sup>is low.
|-
|| Click on '''Quantity''' switch.

Point to (5.0 x 10<sup>-3</sup>)

Point to (5.0 x 10<sup>-13</sup>) and 

point to (28).
|| Then click on '''Quantity(mol)''',
we will see the number of moles of hydronium ion, hydroxide ion and water.
|-
|| Point to '''Linear'''.

Click on '''Linear'''.

Point to '''pH scale'''.

|| Let us change '''Logarithmic scale''' to '''Linear'''.

To do so click on '''Linear''' .

The '''pH scale''' changes to '''Linear''' mode.

We also see that '''pH''' values become '''Linear'''.

But we will not use '''Linear scale''' as

'''pH''' is in '''Logarithmic scale'''.
|-
|| Click on '''H<sub>3</sub>0<sup>+</sup>/OH<sup>-</sup> ratio''' check box.


Point to container.

Point to red dots.

Point to blue dots.
|| Click on Hydronium ion to hydroxide ion ratio '''(H<sub>3</sub>0<sup>+</sup>/OH<sup>-</sup>)''' check box.

A large number of red dots are seen in the container.

These are hydronium ions.

A few blue dots that are seen are hydroxide ions '''(OH<sup>-</sup>)'''. 
|-
|| Click on '''Molecule Count''' check box.

Point to 9.52 x 10<sup>20</sup>.

Point to 9.52 x 10<sup>12</sup>.

Point to 1.66 x 10<sup>25</sup>.
|| To see count of molecules in '''Soda Pop''', click on '''Molecule count''' check box.

Count of hydronium ions, hydroxide ions and water molecules in '''Soda Pop''' is seen.
|-
|| Click on water pump.

Point to '''H<sub>3</sub>0<sup>+</sup>''', '''OH<sup>-</sup>''' and '''H<sub>2</sub>0'''.

Point to '''pH meter'''.
|| Let us see how dilution affects the number of molecules.

Click on water pump, fill the container up to 1 L.

Observe the change in '''Molecule Count'''.

Note the increase in '''pH''' value.

'''pH''' becomes 2.80.
|-
|| '''Slide Number 13'''

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

measure the '''pH''' of '''Blood''' sample.

Observe the change in '''Molecule Count''' and '''H<sub>3</sub>0<sup>+</sup>/OH<sup>-</sup>''' ratio after dilution.
|-
|| Point to '''My Solution''' screen.


Click on '''My Solution''' screen.
|| Now, we will move on to '''My Solution''' screen.

Click on '''My Solution''' screen at the bottom of the interface.
|-
|| Point to '''My Solution''' screen.
|| '''My Solution''' screen has the same tools as that of '''Macro''' and '''Micro''' screens.
|-
|| Point to the graduated container.


Point to the '''pH meter'''.
|| This screen also has some additional tools.

A graduated container on the right hand side of screen.

A '''pH meter''' to adjust '''pH''' directly.
|-
|| Point to the screen.
|| This screen allows direct manipulation of '''pH''' or ion concentration.
|-
|| Click and move '''H<sub>3</sub>0<sup>+'''</sup>and '''OH<sup>-</sup>''' slider.


Click on Black Arrow upwards or downwards.
|| In this screen, we can make a solution of our choice in two ways-

By moving the '''H<sub>3</sub>0<sup>+'''</sup>or '''OH<sup>-'''</sup> slider on '''pH scale'''.

By clicking black arrow upwards or downwards.
|-
|| Move the '''(H<sub>3</sub>0<sup>+'''</sup>) slider. 


Point to '''OH<sup>-'''</sup> slider.
|| Let us move the hydronium ion '''(H<sub>3</sub>0<sup>+</sup>)''' slider upwards.

Notice that, simultaneously Hydroxide ion '''(OH<sup>-</sup>)''' slider also moves downwards.
|-
|| Click on black arrow downwards.
|| Let's make a solution of '''pH''' 4.0 by clicking the black arrow downwards.

This is an acidic solution.
|-
|| Click on '''H<sub>3</sub>0<sup>+</sup>''' and '''OH<sup>- </sup>'''ratio check box.

Click on '''Molecule count''' check box.


Point to 3.01 x 10<sup>19</sup>.
|| Now, Click on Hydronium ion to hydroxide ion '''(H<sub>3</sub>0<sup>+</sup>/OH<sup>-</sup> )''' ratio and '''Molecule count''' check boxes.

Notice that '''Molecule count''' for hydronium ion '''(H<sub>3</sub>0<sup>+</sup>)<sup> </sup>''' is '''3.01 x 10<sup>19</sup>'''.
|-
|| '''Slide Number 14'''

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

Make solutions of '''pH''' 7.0 and 9.0.

Observe and compare the change in molecules.
|-
|| '''Slide Number 15'''

'''Summary'''
|| Let us summarize.

In this tutorial we have learnt about,

interactive '''PhET simulation, pH scale'''.
|-
|| '''Slide Number 16'''

'''Summary I'''
|| Using this simulation we have learnt to-

1. Determine whether a given solution is an acid or a base.

2. Arrange acids and bases according to their strength.

3. Determine the concentration of hydronium ion, hydroxide ion and water at a given '''pH'''.
|-
|| '''Slide Number 17'''

'''Summary II'''
||4. '''pH''' of a solution.

5. Effect of dilution on '''pH''' of solution.

6. '''Logarithmic''' and '''Linear scale'''.
|-
|| '''Slide Number 18'''

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

Please download and watch it.
|-
|| '''Slide Number 19'''

'''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 20'''

'''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 in this forum.
|-
|| '''Slide Number 21'''

'''Acknowledgement'''

|| This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
|-
|| '''Slide Number 22'''

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

More information on this mission is available at

this link.
|-
|| 
|| This is '''Meenal Ghoderao''' from '''IIT Bombay'''.

Thank you for joining.
|-
|}