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

Determination of the Value of the Gas Constant and the Molar Volume of Oxygen at STP

Extracts from this document...


IB Chemistry - Practical Report Name: Chris Bolton Partner: Jamie Gearing Date(s) Conducted: 18/07/04 Topic: Application of Gas Laws Experiment: Determination of the Value of the Gas Constant and the Molar Volume of Oxygen at STP Aim: To experimentally determine the value of (I) the gas constant and (II) the molar volume of oxygen at ?SLC, and therefore to determine the molar volume of an ideal gas at STP. Hypothesis: The empirically determined values for the gas constant and the molar volume of oxygen at SLC (extrapolated to STP) should roughly approximate literature values for the gas constant (8.31 J.K-1.mol-1) and molar volume of an ideal gas (22.4 dm3.mol-1) at STP respectively, to the degrees of accuracy permitted by experimental procedure. Apparatus: MATERIALS: ? 2 grams potassium permanganate (KMnO4(s)) GENERAL: Test tube with a one-holed bung in it, retort stand, boss and clamp, rubber tubing, glass wool, 100 cm3 gas syringe, glass tubing, spatula, electronic balance SAFETY: Lab coat and safety glasses to be worn at all times. Gloves to be worn when handling potassium permanganate. Method: Refer to attached worksheet for given method AMMENDMENTS/ADDITIONS/SAFETY PRECAUTIONS: * Ensure that gas syringe plunger is not in any way impacted by wire safety cord * Ensure that plunger is entirely compressed prior to commencement * Stop heating test-tube once volume is ? 70 cm3 to avoid exceeding syringe capacity * Safety Note: Use protective gloves when handling potassium permanganate Results: Fig. ...read more.


= 0.108/32.00 n(O2) = 27/8000 ? 0.003375 mol Now divide the volume by the number of moles present; (8.25 x 10-5 m3)/(27/8000) = 0.0244 m3.mol-1 = 24.4 dm3.mol-1 The same relative/percentage errors are associated with this figure, since each value is multiplied or divided by the other in much the same fashion. Hence; Total Percentage Error (sum of all % errors): (100/27)+(50/89)+(50/589)+(2/1013) = 4.35 % ?error? = 0.0435 x 24.4 = ? 1.06 Now an absolute error has been found for the experimentally determined molar volume of oxygen at STP, so the value can be accurately expressed as: VM(STP) = 24.4 ? 1.06 dm3.mol-1 at 273 K and 101325 Pa *NOTE: This value was determined independent of the established "R" value, and is based on extrapolated ambient temperature and pressure (at STP, in fact). Comparison with Literature Values: The literature value of the Gas Constant is 8.31 J.K-1.mol-1 at 273 K and 101325 Pa. The empirically determined value found by processing the results of this experiment was 9.07 ? 0.395 J.K-1.mol-1 at 294.5 K and 101300 Pa. Clearly the conditions under which the experiment were carried out differed from STP, so results are already tainted, but the percentage difference is of some interest: ?error? = 9.07 - 8.31 = ? 0.760 relative = 0.760/8.31 = 0.0915 percentage = ? 9.15 % deviation Hence, the empirically determined "R" is approximately 9.15% off the literature value. Interestingly, 4.35% of this error has already been accounted for by systematic error calculations, leaving less than a ?5% deviation. ...read more.


The key improvements to this experiment would therefore include: a) Since STP would be rather difficult to simulate in a school lab, performing the experiment at SLC - with correct temperature and pressure (298 K; 101325 Pa) - is a more plausible alternative. Such a modification would allow the comparison of definite literature values with empirical results. b) Tilting the gas syringes more substantially to reduce effects of gravity on volume c) Removing safety wire holding plunger in syringe and replace with a less tense string to avoid having the syringe inhibited d) Lubricate plunger to avoid friction inhibiting plunger e) Heat the sample more gently and use less of the potassium permanganate in order that all the gaseous oxygen of the sample may be removed and the scale of the syringe is not exceeded f) Allow much more time (in the order of hours) for the apparatus to cool and for the oxygen to reach room temperature and pressure in order that calculations are valid g) Collation of multiple results, or repetition of experiment to ensure a normal distribution of results finds a reasonably accurate mean result and that random errors are gradually reduced in effect h) Use of a larger quantity of potassium permanganate and more accurate gas syringes to reduce the associated percentage errors i) Use of multiple sets of balances (ideally of greater precision) to reduce the associated systematic errors If these improvements were implemented, the accuracy of the results (and the precision with which the empirical values and the literature values matched) would certainly increase. Chris Bolton ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level War Poetry 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 AS and A Level War Poetry essays

  1. Right equation

    Bung To seal the boiling tube and make sure the boiling tube is an airtight seal. Unlike a lid which encloses a boiling tube from the outside without displacing the inner volume. Digital weighting scales to weight copper carbonate to great accuracy.

  2. I need to produce a marketing strategy for a new or existing product. I ...

    To date over two million gas customers have returned to British Gas having tried one or more of the other suppliers. Many of those who have returned have told them that they have done so because: - they did

  1. Determining the Correct Equation for the Decomposition of Copper Carbonate.

    RT Factors to consider: * How will you decompose the compound? I've chosen to use the method of heating the solid copper carbonate and collecting the gas formed. * How are you going to collect the gas? I have decided to use a gas syringe.

  2. Maths Statistics Coursework - Comparing the relationship Between Gas Cost and Temperature

    8 64 85.19 10.6 4 5 -1 1 125.68 5.3 2 12 -10 100 68.42 9.9 8 7 1 1 26.25 15.9 12 1 11 121 74.78 11.4 5 4 1 1 124.99 5.7 3 11 -8 64 71.36 9.2 6 9 -3 9 39.27 15.7 10 2 8 64 70.13 10.5 7 6 1 1 (FIG.2)

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