Identification of Petroleum Hydrocarbons free essay sample

Abstract: Unknown hydrocarbon K was identified by using purification, determination of boiling point by using the capillary tube technique, the calculation of density and obtained refractive index value from the Abbe-3L refractometer. The density was not useful due to an error of the machine but the boiling point and refractive index were used to confirm that the unidentified hydrocarbon K was 2,2 Introduction Thrush is a gasoline additive that is claimed to improve engine performance (Lehman,2009). Gasoline is derived from petroleum and must be refined to be used as a fuel source Straight chain carbons like heptane and hexane burn rapidly causing a shock wave that does not give a good source of power and damages the engine (Lehman,2009). Highly branched hydrocarbons on the other hand burn slower and uniformly not causing a shock wave (Lehman,2009). We will write a custom essay sample on Identification of Petroleum Hydrocarbons or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The octane number of motor fuel measures the ability of the fuel not to cause a shock wave (Lehman,2009). The higher the number the more branched the hydrocarbon (Lehman,2009). The purpose of this experiment is to identify the hydrocarbon in thrust and determine whether or not its octane number is greater than 87. The hypothesis for this experiment was that with the measurement of boiling point, density and refractive index the hydrocarbon can be identified therefore allowing for the determination of the octane number. The strategy of this experiment is using simple distillation in order to purify the substance then using the capillary tube boiling method to find the boiling point of the unknown and then determining the density using the previously learned technique from the first lab Materials and Methods Unknown k was distilled using the technique of simple distillation once it was distilled a portion of the distillate was used to determine the boiling  point using the capillary tube boiling point technique. Another portion of 1 ml was used to figure out the density of unknown hydrocarbon K. The density was measured by weighing out intervals of .2 ml at a time and then graphing the mass and the volumes to get the slope which was the density of unknown K. The last thing done was the refractive index which was done by using the Abbe-3L refractometer. Results The boiling point range for the unknown k was between 48 and 49 degrees centigrade averaging out to be 49 degrees centigrade from the capillary tube boiling point technique. The density of unknown K was . The refractive index was 1.36521 at 20 degrees centigrade. the corrective refractive index was not necessary. finally the unknown was identified to be 2,2 dimethylbutane. Graph 1: The mass weighed from the volumes in intervals of 0.2ml. The slope is the density of unknown K which is 1.1265g/ml Discussion In conclusion unknown K was identified to be 2,2, dimethyl butane because of the refractive index and the boiling point. The refractive index obtained was 1,36521 and the expected was supposed to be 1.3688 since the experimental value was so close to that of the expected it was determined that the unknown was 2,2 dimethyl butane. The boiling point was also an indicator that the unknown hydrocarbon was 2,2 dimethyl butane because the experimental temperature average was 49 degrees centigrade which was exactly that of the temperature of 2,2 dimethyl butane. the density wa not a good indication for which hydrocarbon in table 8.2 because it was well over any of the hydrocarbons in the table. This suggested that there was great source of error when weighing the hydrocarbon. Indeed there was error but it was from the analytical balance which did not settle on a number but went down further and further because the hydrocarbon was extremely volatile. the octane of 2,2 dimethylbutane was dete rmined to be 97 which is greater than 87 suggesting that the hydrocarbon is highly branched making it a hydrocarbon in thrust that will promote an anti-shocking which means it is proven to be good for the engine. Discussion Questions 1. You would correct the refractive index by : 1.3780+(0.00045*(78.2-20)) =1.40419 and the density calculation would be: 0.133/0.200=.665g/ml. The unknown hydrocarbon is not listed. 4. If the density is greater than water then it will remain on the surface of the water causing a problem with the aquatic animals trying to come up to the surface of the water. Will suffocate the water by not allowing for oxygen to be dissolved in the water making it hard for sea creatures to breath. It will possibly create the tar balls as what was said in lecture. 6. a) Dioxane has a boiling point of 101 degrees centigrade just like methylcyclohexane so another property such manipulation of solubility could separate the two from each other because boiling with evaporate both at the same time.