Chemical Bonding : Molecular Shapes PDF

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Chemical Bonding : Molecular Shapes Lab Report...

Description

Experiment #10 Chemical Bonding : Molecular Shapes Dawson College, Department of Chemistry and Chemical Technology General Chemistry, 202-NYA-05, section 00006, fall semester, 2020

Amine Ouachani, 2034815

Date of experiment : 01/12/2020 Rodney S.T. Squire

Date of submission : 11/12/2020

Results

Pre-Lab Questions 1. What is VSEPR Theory? Explain the physical basis of this theory. The VSEPR Theory stands for the valence shell electron pair repulsion theory, which indicates the molecular geometry of molecules in order to minimize electron repulsions the most. The basis of the Lewis structure is incorporated whenever we use VSEPR. However, the molecular links’ positions are modified according to where electron repulsion is minimized the most. These modifications are determined using VSEPR.

Post-Lab Questions 1. What is the difference between the geometric arrangement of electron pairs and the geometric arrangement of atoms? Use the water molecule as an example in your explanation. The difference is that the geometric arrangement of electron pairs is formed by how many paired electrons the central atom possesses, whether they are bonded with another atom or not. However, the geometric arrangement of atoms depends on the paired electrons of the central atom bonded with the surrounding atoms. For example, the water molecule possesses a tetrahedral electron arrangement, while its geometric arrangement is angular (bent), as shown below.

2. Describe the effect that nonbonding electron pairs might have on the molecular geometry. Use water as the example. Nonbonding electrons affect the molecular geometry by shifting the electron bonds to where they are the less repulsive. For example, in water, the central atom (Oxygen) possesses 2 lone paired electrons. These lone paired electrons will shift the bonds between oxygen and hydrogen to the bottom of the molecule , at an angle of 104.5° between the hydrogen atoms, in order to minimize the repulsion between the lone paired electrons and the bond paired electrons of the oxygen as well as the hydrogen.

3. Describe the effect that a second or third pair of shared electrons between two atoms (double or triple bonds) might have on the shape of the molecule. The fact that double or triple bonds are created means that there are less unbonded paired electrons in the molecule. This means that repulsion between the electrons is less likely, resulting in an adjusted molecular shape....