VSEPR Theory Lab Report

1047 Words5 Pages
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…show more content…
Also after understanding what each molecular geometries look like, the next step of the experiment involves miscibility on molecular polarity. Miscibility is the mixture of a liquid with another substance to form a homogeneous solution. Pentane, water, test tubes and food dye are needed in order to start the next portion of the experiment. Measure and place 3 mL of water in the same test tube as 3 mL of methanol. Record any observation in the lab manual worksheet. Add 1 drop of food dye and note whether it miscible or immiscible. Repeat the step again but instead of water and methanol use water and pentane. Also, remember to observe and note down the observation. Clean the lab station by washing all the supplies used and return them to the locker and also liquid should be disposed of in the waste beaker. After cleaning the lab station, gather any clean test tube, ethanol, propanol, water, butanol and food dye to test how chain length affects alcohols in water. To do this next step, add 3 mL of water to the test tube. Record the observation in the lab manual worksheet. Repeat the same process with 3 mL butanol and 3 mL propanol. Dry and clean any materials left on the lab…show more content…
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

    More about VSEPR Theory Lab Report

      Open Document