GChemPaint/C2/Editing-molecules/English

Title of the tutorial: Editing molecules

Author: Madhuri Ganapathi

Key words: Video tutorial, GChemPaint tools- Add an electron pair to an atom, Add or modify an atom, Add a bond or change the multiplicity of the existing one, Add a six membered cycle, Increment the charge of an atom

Visual Cue	Narration
Slide Number 1 Title Slide	Hello everyone. Welcome the tutorial on Editing Molecules in GChemPaint.
Slide Number 2 Learning Objectives	In this tutorial, we will learn to Add unbound electrons on an atom Draw Carbonic acid and Sulphuric acid structures. Add and modify a local charge on a group of atoms
Slide Number 3 Learning Objectives	We will also learn to, Add and modify a local charge on an atom Add cyclic molecules Convert mono-cyclic molecules to bi-cyclic molecules.
Slide Number 4 System Requirement	Here I am using Ubuntu Linux OS version. 12.04 GChemPaint version 0.12.10
Slide Number 5 Pre-requisites	To follow this tutorial you should be familiar with, GChemPaint chemical structure editor. If not, for relevant tutorials, please visit our website.
Switch to GChemPaint application.	I have opened a new GChemPaint application.
	Let's first draw Ammonia structure.
Click on Current element drop down arrow button.	Click on Current element drop down arrow button.
Select N from the table.	Select N from the table. Observe N in the tool box.
Click on Add or modify an atom tool >> click on Display area.	Click on Add or modify an atom tool. Then click on Display area.
Point to NH3	NH3 is seen on the Display area.
Press capital H. Point to the Submenu.	Press capital H. A Submenu with a list of elements starting with H appears.
Select H from the list.	Select H from the list.
Click on Add a bond or change the multiplicity of the existing one tool.	Click on Add a bond or change the multiplicity of the existing one tool.
Click and drag the bonds thrice on Nitrogen atom.	To draw three bonds to Nitrogen atom Click and drag the bonds thrice on Nitrogen atom.
Point to the bonds	Orient the bonds to form a Pyramid like structure.
	Let's add a pair of un-bound electrons on Nitrogen atom.
Click on Add an electron pair to an atom tool >> click on the Nitrogen atom.	Click on Add an electron pair to an atom tool. Then click on Nitrogen atom of Ammonia. Observe the changes.
Point to the unbound electrons.	Note that Nitrogen of Ammonia now has a pair of electrons. This pair does not take part in bonding. This pair of electrons is lone pair.
Slide Number 6 Assignment	As an assignment, Draw Phosphorus trichloride structure Add a pair of un-bound electrons on the Phosphorus atom.
	Now let's draw 'Carbonic acid(H2CO3) and Sulphuric acid(H2SO4) structures.
Slide Number 7 Structures of Carbonic acid and Sulphuric acid.	Here is a slide for, Carbonic acid and Sulphuric acid structures.
	First let's move Ammoniastructure aside. To do so, click on Select one or more objects tool. Then click on Ammonia structure and drag it to one side.
	Now let's draw Carbonic acid structure.
Click on the Current element arrow button >>Select C from the table.	Click on the Current element arrow button. Select C from the table.
Click on Add a bond or change the multiplicity of the existing one tool.	Click on Add a bond or change the multiplicity of the existing one tool.
Click on the Display area. Point to the orientation	Click on the Display area. Orient three bonds in such a way that they form an inverted Y.
Point to the fourth bond.	Draw the fourth bond as a double bond to any one of the bonds.
Click on Current element drop down button.	Now click on Current element drop down button.
Select O.	Select O.
Click on Add or modify an atom tool	Click on Add or modify an atom tool
Point to the cursor.	Place the cursor near the bonds.
Click on the bond positions.	Click on the three bond positions. Carbonic acid(H2CO3) structure is drawn.
	Now let's draw Sulphuric acid structure.
Click on Current element drop down button.	Click on Current element drop down button.
Select S	Select S
Click on Add or modify an atom tool >>Click on the Display area.	Click on Add or modify an atom tool. Then click on Display area. Observe H2S.
Click on the Display area>> Press capital O A Submenu with O and Os opens.	Now anywhere on the Display area press capital O A Submenu with 2 options O and Os opens.
Select O.	Select O.
Click on Add or modify an atom tool >> click on Add a bond or change the multiplicity of the existing one tool.	Click on Add or modify an atom tool. Then click on Add a bond or change the multiplicity of the existing one tool.
In the Property menu >>make the Bond length value to 200 or above.	In the Property menu, increase the Bond length value to 200 or above.
Click on H2S to draw three bonds.	Click on H2S to draw three bonds of OH to S.
Point to positive charge near S.	Observe a positive charge near S. This appears because Sulphur has to satisfy valency of 6.
Click on S and drag the bond to a side without releasing the mouse.	For the fourth bond, first click on S . Now drag the bond to one side without releasing the mouse.
Point to any 2 opposite bonds.	Now let's convert the opposite bonds into double bonds.
Click on Add a bond or change the multiplicity of the existing one tool >>click on the existing bonds.	Click on Add a bond or change the multiplicity of the existing one tool. Then click on the opposite existing bonds of the structure.
Point to the structure	Note that the positive charge is no longer visible. Sulphuric acid structure is complete.
	Next let's add a local charge on the Carbonic acid and Sulphuric acid structures.
Click on Decrement the charge of an atom tool.	To show local charge, Click on Decrement the charge of an atom tool.
Click on two O-H groups.	Click on the two O-H groups of the Carbonic acid structure. Observe that Carbonate ion (CO32-) is formed.
Click on Decrement the charge of an atom tool.	To show local charge on Sulphuric acid structure. Click on Decrement the charge of an atom tool.
Click on the two opposite O-H groups.	Click on the two opposite O-H groups of Sulphuric acid. Observe that Sulphate ion (SO42-) is formed.
Slide Number 8 Assignment	As an assignment, Draw Nitric acid (HNO3) structure Show the local charge on the Nitrate ion(NO-3) Your completed assignment should look like this.
	Let me quickly demonstrate how to add a local charge on an atom.
Press capital N. Point to the Submenu	Anywhere on the Display area, press capital N. A Submenu opens in which we will select Na.
Click on Add or modify an atom tool >>Click on the Display area.	Click on Add or modify an atom tool Then click on the Display area. Sodium atom appears on the Display area.
Click on Increment the charge of an atom tool >>Click on Na.	Click on Increment the charge of an atom tool. Then Click on Na. Observe a positive charge on the Sodium atom.
Point to Decrement the charge of an atom tool.	In a similar way, we can add a negative charge to an atom. This can be done by choosing Decrement the charge of an atom tool.
	Now let's learn to draw Cyclic molecules. For this, we will open a new GChemPaint window.
Click on Create a new file icon on the toolbar.	Click on Create a new file icon on the toolbar.
	Ensure that C that is Carbon is selected as element. Also, ensure that Bond length is 200 or above.
Point to the cycle tools bar in the tool box	The Fourth toolbar in the tool box is Cycle tool There are various tools here that we can use. For eg - Add a three membered cycle Add a four membered cycle and some more cycle tools and then Add a cycle.
Point to Add a four membered cycle tool	We will use Add a four membered cycle.
Click on Add a four membered cycle tool >>Click on the Display area.	So, click on it. Then click on the Display area.
	Let's add atoms to the cycle at the corners.
Right click on any one of the corners >>A Submenu opens.	Right click any one of the corners. A Submenu opens.
Select Atom >>Then click on Display symbol.	Select Atom. Then click on Display symbol.
Show this part fast.	Likewise let's add atoms on all the corners. Obtained structure is Cyclobutane.
	Let's now convert a mono-cyclic compound to bi-cyclic compound.
Click on Add a six membered cycle tool >> click on the Display area.	Click on Add a six membered cycle tool. Then click on Display area.
Click on the cycle bond	Place the cursor on the cycle's bond and click again. Observe the Bi-cyclic compound.
Click on Save the current file icon on the toolbar.	To save the file, Click on Save the current file icon on the toolbar.
Save as dialog box opens.	Save as dialog box opens.
Enter the file name as Editing Molecules >>Click on Save button.	Enter the file name as Editing Molecules Click on Save button.
	Let's summarize.
Slide Number 9 Summary	In this tutorial, we have learnt to, Add unbound electrons on an atom Draw Carbonic acid and Sulphuric acid structures. Add and modify a local charge on a group of atoms
Slide Number 10 Summary	We have also learnt to, Add and modify a local charge on an atom Add cyclic molecules Convert mono-cyclic molecules to bi-cyclic molecules.
Slide Number 11 Assignment	As an assignment Add a seven membered cycle to the Display area Change it to a tricyclic compound.
Slide Number 12 Acknowledgement	Watch the video available at this URL. http://spoken-tutorial.org/ What_is_a_Spoken_Tutorial It summarises the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it.
Slide Number 13	The Spoken Tutorial Project Team: Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to contact@spoken-tutorial.org
Slide number 10	Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at this link http://spoken-tutorial.org/NMEICT-Intro This is Madhuri Ganapathi from IIT Bombay signing off. Thank you for joining.

Contributors and Content Editors

Madhurig, PoojaMoolya