Abstract

The physicochemical properties and mineral contents of ripe and unripe pawpaw and water melon seed oils were evaluated. The physicochemical evaluation showed that the oils have low saponification, low iodine, low peroxide and low acid values. These values indicated that the oils have good commercial values and uses apart from their nutritional values and can also be stored for a long period of time. The assay of mineral contents also showed that the oils contained useful macro and micro nutrients especially high amount of phosphorous which suggests that it can be used to treat hypophosphatemia. The ripe and unripe seed oils have almost the same physicochemical properties which suggest that the oil can be harvested when the pawpaw is ripe or otherwise. The three seed oils have more long chain saturated fatty acid (moderate saponification value) which makes them good oils for soap making. Also their calorific values are high enough to make them a good source of bio-fuels. The oils should be evaluated for toxicological effect before it is recommended for human consumption and its melting point and flash point also be evaluated to know its grade as a biofuel. (1) Give the average capillary rise of water at 25°C, with its uncertainty at the 95% confidence level based on your data. (2) For each alcohol, report the average capillary rise, with the uncertainty at the 95% confidence level at 25°C, in a table that contains all the data, the average and the uncertainty. (3) (a) Assuming the literature value of the surface tension for water is correct allows you to estimate the radius of the capillary. Use the average capillary rise for water (along with its associated uncertainty) to determine the effective radius (and its associated uncertainty) of the capillary you used by solving equation 1.4. (b) Use Eq. 1.5 to estimate the radius of the capillary from the capillary rise of water. Does equation 1.5 give a value that is measurably different from that by using equation 1.4? Explain the answer. If your results show that Eq. 1.5 gives a measurably different result, use it in the following. Otherwise, use Eq. 1.4. (4) Use the average capillary rise of each alcohol from the table (plus the associated uncertainty), the average capillary rise of water (and its uncertainty) and other constants from the literature to derive the surface tension of each alcohol at 25°C. Report the results in a table. (5) In the table you made in question 4, report the literature value of the surface tension of each alcohol. Be sure to reference the literature (not the Internet!!) from which you took these data and use the proper ACS style for references.