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Investigating Molecules Using Chemsketch And Database Lab Report

Decent Essays

Investigating Molecules Using Chemsketch and Database

Prepared for Mrs. Mohoruk

Chemistry 11 SL

Finn White-Robinson

February 15th, 2017

Purpose: The purpose of this lab is to investigate how introducing, but more specifically substituting, a halogen into a molecule will affect the bond lengths and bond angles of that molecule. The molecule we will be working with is Ammonia (NH3) and these halogens will be substituted into the place of a hydrogen. We will investigate the impact of this now attached atom upon the molecule structure.

Plan/Methodology: For this investigation, it is necessary to use a piece of software to accurately model the molecule and measure bond angles. This should provide the data necessary to ascertain …show more content…

Download the correct freeware, Chemsketch, from http://www.acdlabs.com/resources/freeware/chemsketch/
2. Open Chemsketch and draw the correct molecule using the freeware.
3. The molecule must be 3D optimised, so either click in tools and select 3D Optimisation, or use Ctrl-Shft-3.
4. Next a window will pop up requiring the user to decide to either remove all hydrogen atoms and then optimise, or not. Click …show more content…

However, as the halogens within the molecule are being pushed away, any hydrogens still within the molecule also begin to move closer. Overall, though, as halogens were introduced, the bond lengths of the molecule increased, which can be understood due to a variety of factors. For example, due to the decrease of electronegativity within the halogens as you proceed down the group, there is also a larger amount of shielding within the individual atoms. Because of this, when the halogens are being pushed away from the central atom, the hydrogens are being drawn in closer, as they are attracted to the imbalanced, more electronegative side of the atom. In the same thought, two halogens within the molecule will repel each other, which is why in the general formula NX3, we can see this produces the longest bond lengths of all data

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