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

Investigating the effect of different liquid densities on the time taken to release 25 ml of alcohols

Extracts from this document...

Introduction

DESIGN * Research question: * Does the change in liquid densities at the same temperature affect the time taken to release 25 ml of the alcohol from a 50 ml burette? * Variables: * Independent variable: The liquid density / g ml-1. * Dependent variable: The time taken to release 25 ml of the alcohol from a burette / s. * Controlled variables: * The volume of alcohol in a burette / ml. * The temperature of the alcohols / oC. * The absence of unnecessary substances or ions. * The same burette for the entire experiment. * Prediction: * The time taken to release 25 ml of the alcohol from a 50 ml burette is, stated by F. Weinberg (1984) [1], dependent on flow velocity and in particular are very sensitive to small changes in the density difference between the two liquids. * My prediction is, the higher the liquid density is, the more time taken for 25 ml of the alcohol to be released from the burette. The time taken to release 25 ml of alcohol increases in order: Methanol, Ethanol, Propan-1-ol, Butan-1-ol and Octan-1-ol. * Method: * Apparatus: * 50 ml burette (Uncertainty: � 0.500 ml). * Retort stand. * 125 ml ethanol C2H5OH 95.0%. * 125 ml methanol CH3OH 99.5%. * 125 ml propan-1-ol CH3(CH2)2OH 98%. * 125 ml butan-1-ol CH3(CH2)3OH 99%. * 125 ml octan-1-ol CH3(CH2)7OH 94%. ...read more.

Middle

* The burettes and funnels are rinsed carefully with distilled water prior to the experiment to ensure that inside the burettes do not contain any unnecessary substances/ions. If present, they may react with the alcohols to form products which have different liquid density, as opposed to original liquid densities of the alcohols at 20 oC (293 K). * The same burette is used for every measurement. This is because burettes from the same manufacturer cannot be guaranteed to have the same radius of the tips (possessing relatively small values). The use of different burettes can result differences in the time taken for the alcohol to be released. DATA COLLECTION AND PROCESSING * Raw data table: Alcohols Dependent & independent variables Ethanol Methanol Propan-1-ol Butan-1-ol Octan-1-ol Liquid density / g ml-1 at 20 oC (293 K) [4] 0.789 0.791 0.804 0.810 0.826 1st repetition: Time taken to release 25 ml of alcohol from a burette / seconds � 0.0100 39.0 43.0 67.0 82.0 112 2nd repetition: Time taken / seconds � 0.0100 41.0 44.0 69.0 81.0 115 3rd repetition: Time taken / seconds � 0.0100 38.0 46.0 70.0 83.0 111 4th repetition: Time taken / seconds � 0.0100 39.0 42.0 71.0 80.0 114 5th repetition: Time taken / seconds � 0.0100 40.0 45.0 70.0 79.0 110. ...read more.

Conclusion

Overall there are 15 times to add 25 alcohol samples since I decide to investigate 5 different alcohols. The more time I need to add more alcohols into the burette, the more likely inaccuracies to occur. * Improving the investigation: * The procedures can be partially replaced by computer data logging suggested by Laurence Rogers (1995) [5] to prevent uncertainties from human errors when stopping the watch. The experiment can be programmed to collect the data (Time taken for 25 ml of the alcohol to be released from the burette) automatically. * More alcohols with liquid densities within the ranges (The lowest value: 0.789 g ml-1 & the highest value: 0.826 g ml-1) can be tested to fill the 2 gaps between methanol and propan-1-ol, butan-1-ol and octan-1-ol in the presented graph. For instance, penta-1-ol has the liquid density of 0.815 g ml-1 at 20 oC (293 K) [6]. * Pure alcohols should be bought in the same concentration to ensure the reliability of the collected data. Otherwise, diluting the alcohols to the same concentration can be less expensive, yet time consuming. * A larger burette, for instance, with measuring volume of 75 ml (only 2 times to add 5 alcohol samples, 25 ml each) will reduce the times need to pour more alcohols into the burette to 10. Not only this change in equipment may save time of experimenting, but also minimise the uncertainties. ...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. Enthalpy of Combustion of Alcohols Lab

    (4.186 Jg-1k-1) (4.00k) Q = 1674.4 J Q = 1.67 kJ Step 3: Calculating the enthalpy of combustion ?HC = Q/mol ?HC = 1.67kJ 0.00390mol = 428 kJ/mol However it is exothermic, that is why it has to be negative = - 428 kJ/mol Step 4: Calculating the uncertainties Uncertainty for mass of alcohol combusted = (0.02g/0.29g)

  2. Design: Investigating the boiling point different alcohols

    Immediately record the temperature when the alcohol boils. 9. Wait for the test tube to cool down and then discard the remained alcohol. 10. Repeat step 2 to step 9 twice with another test tube (same type) each time. 11. Replace methanol by ethanol, propan-1-ol, butan-1-ol and octan-1-ol in step 1 respectively.

  1. Research question - How many molecules are there in a liquid drop?

    Number of drops 20 drops 40 drops 60 drops 80 drops 100 drops Trial I II III I III III I II III I II III I II III Nature of liquids Water 1.09 1.29 1.07 2.14 2.35 2.58 3.81 3.95 3.85 5.34 5.37 5.35 6.81 6.77 6.72 Glycerine 1.20

  2. IB Chemistry Kinetics Exam Questions and Answers

    Draw a graph that shows the concentration of products with time as a reaction goes to completion. Explain the shape of the graph. At t=0, there is no product. As time passes, the concentration of the product increases. The rate is fast at first because the concentration of the reactants

  1. IB chemistry revision notes

    electrostatic: * Van der Waal's forces: o Electrons in atoms, molecules and ions are free to move around within the atoms. o Van der Waal's forces are caused by the random, instantaneous movements of electrons in a species. When this happens it can become a temporary dipole; if another species

  2. Combustion of alcohols lab report

    4638 65.22 Octanol 11336.91 130 4210.85 5294 79.54 Nonanol 7341.63 144 5564.18 5947 93.56 Table to show energy differences between preceding alcohols Name of alcohol Number of Carbon atoms Energy liberated (J) Energy difference between preceding alcohol Ethanol 2 7952.37 Propanol 3 8587.89 635.52 Butanol 4 7984.47 603.42 Pentanol 5

  1. How does density of a liquid affect the volume of its drop

    However, there is a slight anomaly where the volume of the drop decreases and increases again rather than a smooth curve upwards. This is due to the errors made in the experiment Conclusion Although there were a few anomalies, my hypothesis proved to be correct because the volume of a drop did generally increase as the density increase.

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

    For example Ethanol has the formula C2H5 OH. The walues of each bonds are presented bellow, and by just looking at them and thinking about the chain lenght of ethanol,methanol,propanol,butanol and pentanol respectively, it can be concluded that pentanol will have the longest chain, therefore the strongest one and so

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