The VSEPR Theory: Lewis Structure And Miscibility On Molecular Polarity

Introduction The VSEPR Theory for this experiment stated that electron group repels against each other and they occupy a lot of space. Scientists use VSEPR Theory to determine the molecule’s geometry by counting the number of electron domains that surround the central atom. Electron domain can be described as a lone pair, single, double and triple bond, and also even free radical. Lone pairs tend to occupy a lot of space and lower the angle of a bond, which gives molecular geometry. Lewis structure help determine the molecular geometries, 3D structure, and distribution of electrons in order to understand the chemical properties of reactivity and molecules like texture and microstructure. One of the most important influences
Table 3 describes each observation. From observing how each substance reacts with one another, a conclusion that states that one was miscible and the other two systems were immiscible can be made. Methanol was a polar molecule while pentane was nonpolar. This matches the hypothesis which states that like dissolves like, polar cannot mix with nonpolar. Ex. oil and water cannot mix because water is polar while oil is nonpolar. The third system allowed 3 substances to be ranked from least to a greater polar molecule. Water is more polar than pentane and pentane is less of a polar molecule than methanol when it comes to comparing the mixture of water/pentane and the mixture of pentane/methanol. When food dye was added, it was able to form a homogeneous mixture of food because the food dye was a polar molecule, which made it water soluble. The next part of the lab was spent observing the effect chain length has on miscible alcohol in water. The result in table 4 matches the hypothesis that the longer hydrocarbon chain stays in a molecule, that molecule will become less polar. This hypothesis sort of made sense, since hydrocarbon is a nonpolar molecule while the alcohol contains oxygen making it a polar molecule. The longer the chain, the less effective it will be to the polar side of the molecule. Methanol looked like an outlier because it doesn’t have that much hydrocarbon and in the first part of the experiment it was to mix with water, but when it was recreated for the second part of the experiment a layer formed. Using the knowledge gained from this lab experiment it can be predicted that the longer hydrocarbon remains in alcohol, the more likely it will decrease the