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

Determining the Concentration of Calcium Carbonate in an Unknown Substance through the Methods of Titration Aim:

Extracts from this document...


Amrit Warraich September 30th 2009 Chemistry SL Mr. Ochola Titration Lab Problem Determine the concentration of the unknown ethanoic acid solution by titrating with a known concentration of sodium hydroxide Equipment and Materials * Unknown ethanoic acid * 50cm3 burette * 250cm3 Erlenmeyer flask * 100cm3 beaker (for CH3COOH) * 200cm3 beaker (for NaOH) * 100cm3 beaker (for waste) * Standardized sodium hydroxide solution * Burette clamp * Retort stand * Phenolphthalein indicator * 50cm3 graduated cylinder * Distilled water (to rinse the flask) Procedure: To begin with, obtain approximately 200 cm3 of sodium hydroxide solution. Then, set up the retort stand and burette clamp as indicated in the diagram below. Using two 10 cm3 aliquots of the NaOH solution, rinse the burette twice. Next, fill to above the 0.00cm3 mark and drain down to below the 0.00cm3 mark in order to remove any air bubbles. After that, transfer 50 cm3 of the unknown acid into the 250cm3 flask. Into the same flask, place 2 drops of the phenolphthalein indicator. Finally, add sodium hydroxide from the burette until you reach the endpoint. Procedural Notes To accommodate for the sodium hydroxide that splashes to the sides of the flask, distilled water was used. ...read more.


The following table represents the results. Results for the calculations of the concentration of ethanoic acid used in each trial Trial Concentration of CH3COOH / mol dm-3 CH3COOH Uncertainties / % 1 0.913 1.3 2 0.913 1.3 3 0.909 1.3 4 0.904 1.3 Average 0.910 1.3 Conclusion: In conclusion, the result of this lab indicates that the concentration of CH3COOH is 0.910 mol dm-3. Using this value, and the actual value of ethnoic acid, 0.9190 mol dm-3 �0.0004 mol dm-3, percent error was calculated as follows: With this, we see that the percent of uncertainties is greater than the percent error. The percent of uncertainties represents the random errors, in which the measured value can either be bigger or smaller than the accepted value, due to an imprecise measurement. To improve these random errors, it is necessary to use more precise equipment and/or repeat measurements. One example of this would be to use a pipette instead of a graduated cylinder, especially because ?0.4 cm3 is a relatively large uncertainty. Consequently, the use of such equipment led to the percent of uncertainties being greater than the percent error. This means that the random errors cover for the errors in this lab. However, there are a couple potential systematic errors that should be appointed in this lab. ...read more.


To improve this, it may be suggested that rinsing the burette 4 times is more sensible, even though it is time consuming. A final systematic error comes when transferring the ethanoic acid from the graduated cylinder. When this happens, some of the ethanoic acid may be retained in the graduated cylinder. This is a systematic error as this always leads to a smaller volume of ethanoic acid than measured. To improve this error, one may pour a tiny bit more than 50 ml of ethanoic acid, and measure that as 50 ml of ethanoic acid. Improving this error leads to a larger volume of ethanoic acid, a lower concentration of ethanoic acid, and once again, an increase in percent error. All in all, it is very interesting how knowing the amount of one substance can help determine the amount of another substance, although it is a topic that appears frequently in chemistry. In this case, knowing the number of moles of sodium hydroxide enabled us to know the concentration of the ethanoic acid. Furthermore, this lab helps one enhance their knowledge on the difficulty of setting up a lab. By reviewing and understanding the errors to a lab, one can relate the improvements to future labs. In a nutshell, this lab exemplified the process of titration, and how useful it can be. ...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. Aim: To determine the concentration of chloride ions in sea water by titration ...

    Thus, when comparing, an assumption is made that the chlorinity of sea water is homogeneous across all seas. 2) Further assumption was made that the titration was carried out under conditions of pH 6.5 - 9. At higher pH silver ions may be removed by precipitation with hydroxide ions, and

  2. Enthalpy Change Design Lab (6/6)How does changing the initial temperature (19C, 25C, 35C, and ...

    were poured into the clean, doubled polystyrene cup, containing the magnetic stirring bar that was already spinning, with the electrically powered stirrer set at a speed of medium. 12. The temperature probe that was being used to monitor the temperature of the 40.0 cm3 solution of 1.00 mol dm-3 HCl(aq)

  1. IB chemistry revision notes

    * Lewis structures o Lewis states the idea that atoms tend to bond in order to have eight electrons in the outer shell. This idea became known as the octet rule. E.g. Fluorine: or * Covalent Bond Lengths o The minimum distance between the two nuclei of the atoms is 1 covalent bond length.

  2. Determining the Percent Yield of Calcium Carbonate

    10-2 mol Therefore, there are 1.88 � 10-2 moles of calcium chloride in the experiment.

  1. pKa. When constant successive portions of Sodium Hydroxide are added to Acetic Acid; how ...

    When the liquid turned pink the final pH was recorded in the results table. Also record the final reading of the burette. The Rough Titration is only an indication and so should not be used in data analysis. 11. After the Rough Titration, the solution in the conical flask was discarded in the sink.

  2. Aim. To find the identity of X(OH)2 (a group II metal hydroxide) by determining ...

    the same brand. By using the same batch ensures that the reactant concentration is the same. If another batch were to be used causes the concentration to differ. This causes the HCl obtained to be different. 3.Same source of X(OH)2 Using the same batch of X(OH)2 or from the same brand will control this.

  1. To determine the molecular mass of an unknown alkali metal carbonate, X2CO3.

    Mass of substance Z used = 1.5g Trial 1 Trial 2 Trial 3 Volume of substance Z solution (±0.03cm3) 25.0 25.0 25.0 Volume of HCl required for neutralization (±0.10cm3) 27.6 28.1 27.9 Mass of substance Z used = 2.0g Trial 1 Trial 2 Trial 3 Volume of substance Z solution (±0.03cm3)

  2. Experimental Molar Enthalpy of Neutralization for Sodium Hydroxide Solution

    By increasing the pressure, the reaction rate is increased and more reactions take place. As a result of a larger quantity of reactions occurring at 101.9kPa than at the standard SATP conditions, there will be a greater change in enthalpy at 101.9kPa.

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