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Intermolecular Forces and the Evaporation of LiquidsExperiment 9*1Cindy NguyenCHEM 117-509Tyler Nardecchia Summary:The purpose of this experiment was to determine how the strength of intermolecular forces varied based on how quickly certain liquids evaporated and how much the temperature changed during evaporation. In Part A of the experiment, six different liquids were given, two being alkanes (pentane and hexane) and four being alcohols (ethanol, propanol, butanol, and methanol). Given two temperature probes, each probe was wrapped with filter paper and secured with rubber bands then dipped into two different liquids from those given. Then data was collected in the form of time vs. temperature and then stopped as soon as the liquid reached its minimum temperature and began to increase again. This process was repeated until the all the liquids had been tested. The significance of this first part was to relate how quickly the substanceevaporated and its change in temperature to the strength of its intermolecular forces. It was concluded that those substances without hydrogen bonds tended to evaporate faster and had a higher change in temperature then those with hydrogen bonds. N-hexane and n-pentane did not have hydrogen bonds as they reached their minimum temperature (evaporated) much quicker andtheir temperature change was significantly higher being a change of 17.5°C and 22.4°C respectively, compared to the alcohols which took much longer to evaporate and did not have as 1 Primary Author
large of a change in temperature being 6.1°C for l-propanol, 10.7°C for ethanol, 3.8°C for l-butanol and 13.9 for methanol. In Part B, 4 water baths were prepared each with different temperatures ranging from 0-5°C, 10-15°C, 20-25°C, and 30-35°C. An Erlenmeyer flask was then injected with ethanol from a syringe and then immersed into each of the water baths. The