Snehalathak at 08:17, 15 February 2023

2023-02-15T08:17:02Z

Madhurig at 09:36, 12 January 2023

2023-01-12T09:36:04Z

Madhurig: Created page with "Title of script: Molecules and Geometry Author: Radhika Yadav Keywords: PhET simulation, molecules, molecular geometry, electron geometry, molecular structure, bonds, bond a..."

2023-01-12T09:35:28Z

Created page with "Title of script: Molecules and Geometry Author: Radhika Yadav Keywords: PhET simulation, molecules, molecular geometry, electron geometry, molecular structure, bonds, bond a..."

New page

Title of script: Molecules and Geometry

Author: Radhika Yadav

Keywords: PhET simulation, molecules, molecular geometry, electron geometry, molecular structure, bonds, bond angles, lone pairs, VSEPR theory, spoken tutorial, video tutorial.

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

'''Title Slide'''
||Welcome to this Spoken Tutorial on '''Molecules and Geometry'''.

|-
||'''Slide Number 2'''

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

* Add and delete bonds and lone pairs
* Identify different molecular geometries
* Differentiate between electron and molecular geometries.

|-
||'''Slide Number 3'''

'''System Requirements '''
||This tutorial is recorded using,

macOS Catalina version 10.15.7

Google Chrome version 101.0.49

|-
||'''Slide Number 4'''

'''Pre-requisites'''

'''https://spoken-tutorial.org'''

||To follow this tutorial,

Learners should be familiar with topics in basic chemistry.

Please use the link below to access the tutorials on PhET simulations.

|-
||'''Slide Number 5'''

'''Link for PhET simulation'''

'''https://phet.colorado.edu/en/simulations/molecule-shapes'''

||Please use the given link to download the '''PhET''' '''simulation'''.

|-
||'''Slide Number 6'''

'''PhET simulations'''

||In this tutorial, we will use,

'''Molecule Shapes''' '''PhET simulation.'''

|-
||Point to the simulation in the Downloads folder

'''Molecule Shapes''' '''simulation.'''

||I have already downloaded the '''simulation''' to my '''Downloads''' folder.

|-
||Double click on the '''molecule-shapes_en.html''' file
||To open the simulation, double click on the '''molecule-shapes_en.html''' file.

The file opens in your default browser.

|-
||Point to the simulation interface
||This is the interface of the '''Molecule Shapes''' simulation.

|-
||Open Settings menu at the bottom right.

Choose Options >> select '''Projector Mode'''.

Click on X button.
||Click on the '''Settings '''menu list next to the PhET logo at the bottom right.

Choose '''Options '''and then check on '''Projector Mode'''.

This will display the simulation in a light background.

Close the menu.

|-
||Point to each screen
||The interface has two screens,

'''Model''' and '''Real Molecules'''

|-
||Click on the '''Model''' screen
||Click on the '''Model '''screen.

|-
||Point to the molecule in the centre of the screen
||In the centre, we have a model molecule.

We can add and delete bonds and lone pairs to this molecule.

|-
||Point to the '''Bonding''' box at the top right.

Click on the bond type to add to the molecule.

Click the red cross button to remove the bond.
||At the top right, we have '''Bonding''' box with single, double and triple bonds.

Click on the bond type to add to the molecule.

We can remove the bonds using the red cross button next to the bond type.

|-
||Point to the '''Lone Pair''' box

Click on the icon to add a lone pair.

Click on the red cross button to remove it.

Show arrow annotation to the violet ball in the model(3.01 to 3.12 min)
||Below the '''Bonding''' box, we have the '''Lone Pair''' box.

We can add a lone pair to the molecule by clicking on the icon.

We can remove it by clicking on the red cross next to it.

A lone pair is an electron pair in the outermost shell of an atom.

It is bonded to the central atom in a molecule.

|-
||Point to the '''Remove All''' option
||The '''Remove All '''button removes all atoms and their bonds in the molecule.

|-
||Point to the '''Options''' box
||'''Options''' box at the bottom, has '''Show Lone Pairs,''' and '''Show Bond Angles''' checkboxes.

We can use these check boxes to show and hide the details.

Bond angle is the angle between two bonds that share a common atom.

|-
||Point to the '''Name''' box at the bottom right
||The '''Name''' box at the bottom left has

'''Molecule Geometry''' and '''Electron Geometry '''checkboxes.

Here, geometry means the three-dimensional arrangement of atoms in a molecule.

'''Molecule geometry''' is found using only the bonds in a molecule.

'''Electron geometry''' is found using the bonds and electron pairs in a molecule.

|-
||Click the '''reset''' button.
||The '''reset''' button will take us back to the start of the simulation.

|-
||Check the '''Molecule Geometry''' and '''Electron Geometry''' checkboxes
||Check the '''Molecule Geometry''' and''' Electron Geometry''' checkboxes.

Both are '''Linear''' for this molecule.

|-
||Check the '''Show Bond Angles''' checkbox.

Point to the bond angle of the bond.
||Check the '''Show Bond Angles''' checkbox.

The bond angle is shown as 180 degrees.

|-
||Click on the double bonded atom in the '''Bonding''' box
||Let us add a double bonded atom to the molecule.

|-
||Point to the '''Name''' box
||The '''Molecule''' and '''Electron''' geometries are '''Trigonal Planar'''.

|-
||Point to the molecule
||The bond angle between each bond is 120 degrees.

|-
||Click on the lone pair atom in the '''Lone Pair''' box
||Let us add a lone pair of electrons to the molecule.

|-
||Point to the '''Name''' box
||The '''molecule geometry''' is '''Trigonal Pyramidal'''.

However, the '''Electron geometry '''is now '''Tetrahedral'''.

|-
||Point to the molecule
||The bond angle between each bond is 109.5 degrees.

|-
||Click on the triple bonded atom in the '''Bonding''' box
||Let us now add a triple bonded atom to the molecule.

|-
||Point to the '''Name''' box
||The '''Molecule geometry '''is '''Seesaw'''.

The '''Electron geometry '''is '''Trigonal Bipyramidal'''.

|-
||Point to the molecule
||The bond angle between a single bond and the double bond is 120 degrees.

All other bond angles are 90 degrees.

|-
||'''Slide Number 7'''

'''Assignment '''

* Molecule- Bent, Electron- Tetrahedral
* Molecule- Linear, Electron- Trigonal Bipyramidal
* Molecule- T-Shaped, Electron- Octahedral

||As an assignment, build molecules that have the following geometries.

|-
||Click on the '''Real Molecules''' screen
||Click on the '''Real Molecules''' screen.

The screen has some new tools.

|-
||Point to the '''Real''' and '''Model''' options at the top
||There are two options to view the molecule at the top.

The first is the '''Real''' option to show the actual shape of the molecule.

|-
||Select the '''Model''' option

Select the '''Real''' option
||The second is the Model option to show the shape predicted by the '''VSEPR''' model.

It stands for '''Valence Shell Electron Pair Repulsion''' model.

There are repulsions between bond pairs and lone pairs.

'''VSEPR''' assumes that these pairs will arrange themselves to minimize the repulsion effects.
|-
||Point to the '''Molecule''' box
||At the top right, we have a '''Molecule''' dropdown.

We can select a real molecule from the given drop down list.

Water molecule (H<sub>2</sub>O) is selected by default.

|-
||Point to the molecule
||This is the water molecule.

It has 2 single bonded atoms and 2 lone pairs.

|-
||Open settings menu and select Show Outer Lone Pairs

Click on X button.
||Click on the '''Settings''' menu list next to the PhET logo at the bottom right.

Choose '''Options''' and then check on S'''how Outer Lone Pairs'''.

This will display lone pairs of all the atoms in the molecule.

Close the menu.

|-
||Point to the molecule
||In the water molecule, only oxygen atom has 2 lone pairs.

|-
||Check the '''Molecule Geometry''' and '''Electron Geometry''' checkboxes
||Check the '''Molecule Geometry''' and '''Electron Geometry''' checkboxes.

The '''Molecule Geometry''' is''' Bent'''.

The Electron Geometry is Tetrahedral.

|-
||Check the '''Show Bond Angles''' checkbox
||Check the''' Show Bond Angles''' checkbox.

|-
||Point to the molecule
||The bond angle between the two single bonds is 104.5 degrees.

|-
||Click on the '''Model''' option
||Click on the Model option.

|-
||Point to the molecule

||The '''VSEPR''' model predicts the bond angle to be 109.5 degrees.

We have seen the actual angle is 104.5 degrees.

This is because a water molecule has 2 lone pairs.

The repulsion between the lone pairs causes distortion in the actual bond angle.

|-
||Click on the '''Real''' option
||Click on the '''Real '''option again.

|-
||Select '''XeF4''' molecule from the drop down list
||Let us select another molecule from the drop down list.

|-
||Point to the molecule
||This is '''Xenon tetrafluoride''' (XeF<sub>4</sub>) molecule.

|-
||Open '''Settings''' menu and unselect '''Show Outer Lone Pairs '''check box.
||We can hide the outer lone pairs of the molecule.

|-
||Point to the molecule
||The molecule has 4 single bonds and 2 lone pairs on the central atom.

|-
||Point to the '''Name '''box
||The Molecule Geometry is Square Planar.

The Electron Geometry is Octahedral.

|-
||Point to the molecule
||Click on the screen near the molecule to move the molecule around.

Change its perspective such that all bond angles are visible.

The bond angle between each of the four single bonds is 90 degrees.

|-
||Click on the '''Model''' option
||Click on the''' Model '''option.

|-
||Point to the molecule
||In this case, the bond angle remains the same.

There is no lone pair-lone pair or single bond-lone pair repulsion.

|-
||'''Slide Number 8'''

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

Check the geometries of all remaining molecules in the list.

Compare their real and model-predicted bond angles.

Explain the reasons for the differences.

|-
|| Only Narration.
||With this, we have come to the end of this tutorial.

Let us summarise.
|-
||'''Slide number 9'''

'''Summary'''
||In this tutorial, we have learnt how to:

* Add and delete bonds and lone pairs
* Identify different molecular geometries
* Differentiate between electron and molecular geometries.

|-
||'''Slide number 10'''

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

Please download and watch it.

|-
||'''Slide number 11'''

'''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 12'''

'''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.

The Spoken tutorial project will ensure an answer.

You will have to register to ask questions.

||Please post your timed queries in this forum.
|-
||'''Slide number 13'''

'''Acknowledgement'''

||The Spoken Tutorial project is funded by the Ministry of Education, Government of India.

|-
||'''Slide number 14'''

'''Thank you'''
||This is Radhika Yadav, a FOSSEE summer fellow 2022, IIT Bombay signing off.

Thanks for joining.
|-
|}

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← Older revision		Revision as of 09:36, 12 January 2023
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	Keywords: PhET simulation, molecules, molecular geometry, electron geometry, molecular structure, bonds, bond angles, lone pairs, VSEPR theory, spoken tutorial, video tutorial.		Keywords: PhET simulation, molecules, molecular geometry, electron geometry, molecular structure, bonds, bond angles, lone pairs, VSEPR theory, spoken tutorial, video tutorial.
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PhET-Simulations-for-Chemistry/C2/Molecules-and-Geometry/English - Revision history

Snehalathak at 08:17, 15 February 2023

Madhurig at 09:36, 12 January 2023

Madhurig: Created page with "Title of script: Molecules and Geometry Author: Radhika Yadav Keywords: PhET simulation, molecules, molecular geometry, electron geometry, molecular structure, bonds, bond a..."