• 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. IB chemistry revision notes

    The lone pair of electrons repel other bonds further away than normal bonds. This gives a V-shaped molecule that is polar. The bond angles between the lone pair and a bond is >120�. The bond angle between the two bonds is <120�.

  2. Hous Process for producing Sodium Carbonate

    The Chinese government had to import Sodium Carbonate (Na2CO3) from England which was expensive. Hou's process helped China develop a cheap way to make Sodium Carbonate (Na2CO3). For China, Hou's process is far superior to the Solvay process because it upgrades the process of making Sodium Carbonate (Na2CO3). Other benefits are that the by-product of Hou's process is ammonium chloride (NH4Cl)

  1. Aim: Using an iodine clock reaction to find the order of hydrogen peroxide and ...

    This is especially significant for the experiments in which H2O2 was increased since these experiments were often marginally faster, meaning that this error could have resulted in an incorrect reading and thus an incorrect trend. Data Set Limitations Not significant since enough data was collected to conclude that H2O2 was first order and that CH3COOH was 0 order.

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

    The Titration was continued until the pH reached 12, the final burette reading was also recorded 15. This titration process (steps 11-14) was repeated another two times, allowing more reliable results. 16. After the Titration the benches were wiped down using paper towels, the solution was discarded in the sink and the glassware was placed in the designated container.

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

    25.0 25.0 25.0 Volume of HCl required for neutralization (±0.10cm3) 37.2 36.8 37.3 Mass of substance Z used = 2.5g 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)

  2. The use of volumetric flask, burette and pipette in determining the concentration of NaOH ...

    HCl H+ (aq) + Cl- (aq) 2. NaOH Na+ (aq) + OH- (aq) The hydrated proton, H+ (aq), has been named the hydronium ion and is often written H3O+. The dissociation of HCl, using this convention, is shown as below: 1. HCl + H20 H3O+ + Cl- Water is partially dissociated into ions, is shown as below: 1.

  1. The purpose of this experiment is to determine the concentration of a solution of ...

    So that there is no expansion of volume of the solution which can lead to inaccuracies in the concentration of the acid. 8. Systematic errors such as bubble in the burette will lead to an increased reading of the volume of the solution used, which will cause error in the calculation of the concentration of the NaOH solution.

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

    There was also soot produced on the tubes with a bigger alcohol molecule alcohols, which suggests an incomplete combustion . Burning of soot means that more energy is gained. One reason why the results obtained were inaccurate is that some of the heat liberated was used to vaporise the liquid prior to its combustion.

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