• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Biodiesel Investigation - How the concentration of Potassium Hydroxide solution would affect the yield of biodiesel when transesterified with a standard sample of vegetable oil .

Extracts from this document...


11th May 2015 Biodiesel Experiment Introduction ?Biodiesel is a clean burning renewable fuel made using natural vegetable oils and fats.1 Biodiesel is a revelation to chemists, engineers and environmentalists who are looking for more sustainable ways to make use of fuels. Since it is a natural and renewable fuel, it can be fitted in as a substitute for petroleum diesel, which is the substance conventionally used in automobile transport. Biodiesel is normally utilised as a replacement for petroleum diesel fuel or can be blended together with petroleum diesel fuel in any ratio. Biodiesel is a biodegradable substance with a lower toxicity in comparison to petroleum diesel fuel and is preferred as it is safer to handle since there is little human risk involved in its handling. The use of biodiesel as a petroleum substitute reduces the degree of exhaust emission. Biodiesel are notorious for their easy use in terms of how they can easily be pumped and stored in existing engines without having to make major industrial alterations to the engines themselves. They are usually blended together with petroleum fuels in order to create the optimal usage in engines. The output yield of biodiesel is I had never really heard of biodiesel until it was a topic covered in school. After finding out what biodiesel was, I looked into the IB chemistry syllabus to see what points it had on biodiesel and looked further into the applications of biodiesel as well as the process of transesterification and what is involved. My personal interest was sparked from my curiosity of how to obtain my own sample of biodiesel after I found out about its many uses. My high school chemistry department provided us with a set of materials and allowed us to investigate our own ways of obtaining biodiesels and I was keen to see what I could do with a sample of this versatile substance. ...read more.


It is also advised to wear lab coats as products of transesterification may permanently stain clothing. Fortunately, there are no ethical concerns involved as only vegetable oil is being used and no animal substances. The biodiesel substance is biodegradable and can be easily disposed of in organic waste. *Cleaps cited in Bibliography ________________ Analysis: Raw Data: Concentration of KOH (%) (±0.052)* Mass of total material(±0.005g) Mass of Total Substance &Biodiesel (±0.005g) Mass of Biodiesel (±0.005g) Volume of Biodiesel (±0.20ml) Final Temperature of Oil Mixture (±0.5ºc) 1 27.167 33.116 5.952 4.40 27.0º 2 26.989 31.982 4.993 4.00 28.0º 3 27.225 34.070 6.845 6.10 39.0º 4 27.169 34.982 7.813 6.40 37.5º 5 27.333 35.305 7.972 6.50 38.0º Qualitative Observations: * In all tests after the oil was placed into the centrifuge, a gunky substance was formed from the separation into two layers, one being the biodiesel and it can be assumed that the gunky substance was glycerol (used in soaps). At times the position of the magnetic stirrer was not in place for some results, which may be a result of random error (anoma Error Calculations on Mass Example % Yield Calculations of Biodiesel 1% Concentration: Example Calculation [(0.052 ÷ 1.000) x 100%] + [(0.2 ÷ 10) x 100] + [(0.2 ÷ 1.5) x 100] + [(0.005 ÷ 5.962) x 100] = 5% + 2% + 10% + 0.08% = 17.08% Uncertainty ≈ 17% Absolute Uncertainty for 1% Concentration yield: 5.95g ± 20% (1sf) 1% Concentration Solution: Mass of biodiesel Extracted: =5.952 (±0.005)g Total mass of oil Mixture (Products from transesterification reaction) 100 x (5.952 ÷ 33.119) (±0.1 *100) Approx 18% Yield (±0.3%) * lies) in results such as the 2% concentration. * The temperature of the magnetic stirrer would be set higher than 31º, and many of the substances would exceed or be under the temperature of 31º before the actual reaction began. * The volume of the oil and KOH mixture used in the second test may not have been the same amount as the first, which would cause an error in the percentage yield of biodiesels. ...read more.


To improve on this and reduce this uncertainty, a combustion test would need to be done on the biodiesel, as it is known to be flammable. The unknown substance should be tested with a flame test and if it burns, should be included in the yield measurements of biodiesel. Using Apparatus with a lower uncertainty for measuring out KOH - methanol substance The 10ml measuring cylinder used had an uncertainty of 0.2, which for 1.5cm3 of solution, was extremely high as a percentage uncertainty. Since this was used for all tests, it must be noted that this was also a contributing factor to the systematic error obtained for each test. To improve this, a different (more precise) piece of measuring apparatus, i.e a burette should?ve been used as it has an uncertainty of 0.05, which would?ve quartered the uncertainty on the potassium hydroxide mixture, and reduced the total uncertainty. Improper placement of beaker on magnetic stirrer Due to time limitations for conducting the experiment, multiple groups had to share the stirrer and therefore place two beakers with magnetic flea?s (capsules) atop the stirrer. This interfered with the ability for the maximum biodiesel output to be produced for each result, and since this only occurred for certain tests, would?ve contributed to any random errors present. To target this limitation, the best solution would be to find time to work on the experiment individually, so that the magnetic stirrer could be used for only one beaker. Impurity on biodiesel The substance measured may not be entirely biodiesel, but instead a mixture of biodiesel and glycerol that may have been extracted without notice. This would?ve caused a higher percentage yield of biodiesel to be measured rather than the actual amount. To add on to this limitation, the reason for an impurity would most probably be from a difficulty in distinguishing between the biodiesel and layer of glycerol. Any filtration process that could separate the biodiesel and the glycerol effectively, would be appropriate. The mixture should undergo centrifugation multiple times in order to separate the layers more clearly. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Chemistry essays

  1. Investigate the rate of reaction of luminol in various factors. The objective was to ...

    Repeat the procedure with 4.5cm3, 4cm3, 3.5cm3, 3cm3, 2.5cm3, 2cm3, 1.5cm3, 1cm3 and 0.5cm3 of luminol solution, add water to it such there is 5cm3 of luminol solution in each test tube. The table should be drawn as below: Concentration of luminol solution 10% 20% 30% 40% 50% 60%

  2. Determination of potassium hydrogen carbonate into potassium carbonate

    (as shown above for this reaction). Error Type of error Quantity of error Explanation for error Improvements Measurement in measuring cylinder Systematic error � 0.5 cm3 Equipment limitation, this is because the line where each of the reading might not be precise. i.e. the manufacturer has not placed the line at the exact place on the measuring cylinder.

  1. A comparison of various proprieary antacids

    * On addition of sodium hydroxide, there was a colour change from transparent lime green to light brown. Zolicid Gel: * There was a moderate reaction between hydrochloric acid and Zolicid gel, and a cream suspension was formed. * On addition of sodium hydroxide, the phenolphthalein indicator experienced a colour change from cream to pinkish white.

  2. IB chemistry revision notes

    o P1V1 = P2V2 * Charles's Law o Pressure constant o For fixed mass of gas the V is directly proportional to T o * Pressure Law o Volume Constant o Maxwell-Boltzmann Energy Distribution Curves 1. Raising temperature shifts the peak to the right (not as tall, but wider) 2.

  1. Hydrogen Gas Collection Lab CE (6/6) A sample of solid magnesium ribbon, measuring approximately ...

    the region - meaning it was derived from a local organisation tracking atmospheric conditions. This is a source of error because the pressure may have changed from the time the measurement was taken, and the pressure within the investigation environment is likely not equal to the atmospheric pressure that was measured earlier, at a different location.

  2. The aim of this experiment is to examine the enthalpy of combustion of the ...

    are the following : Methanol: - 726 kJ/mol Ethanol: - 1367 kJ/mol Propan-1-ol: - 2021 kJ/mol Butan-1-ol: - 2676 kJ/mol Pentan-1-ol: -3330.63 kJ/mol According to the results it is clear that there were some mistakes / errors in the experiment.

  1. Percent Yield Lab. This experiment has proven that KI is the limiting reagent ...

    This is because KI is the limiting reagent and Pb(NO3)2 is the excess. When this chemical reaction occurred and two reactants mix, theory was able to determine the amount of each product formed using stoichiometric calculations. The maximum value of the final product is limited to the limiting reagent not the reagent in excess.

  2. Measuring the fatty acid percentage of the reused sunflower oil after numerous times of ...

    As HDLs have a much higher percentage of proteins as LDLs, they can prevent the build-up of cholesterol in the arteries. The lower percentage of lipids in HDLs means these can absorb more cholesterol and hence carry it from the arteries.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work