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

Acid Base titration to determine the percentage by mass of calcium carbonate in an egg shell .

Extracts from this document...

Introduction

Gerald Veliz 11°C - IB Davy College Acid-base titration Investigation # 6 GERALD VELIZ 06/06/2012 ________________ Acid-base Titration Objectives: 1. To determine the percentage by mass of calcium carbonate in an egg shell . Results: The first product is composed by the reactants: 0.6 grams of a ¨impure¨ sample of calcium carbonate and 20cm3 of 1.00 mol/dm3 hydrochloric acid solution, and it forms the following equation: CaCO3 + 2HCl → CaCl2 + CO2 + H2O , which will be later use to complete the objective of the experiment. As having the acidic solution, sodium nitrate of 0.100 mol/dm3 was used to titrate the hydrochloric acid, and with the use of Vernier instruments, the exact volume of sodium nitrate needed to reach the equivalence point, would be obtained. ...read more.

Middle

The pH of the final solution is now alkaline because after the dissociation of the hydrogen ion of the acid which was dissolved in water, it then forms hydroxide ions, which makes the pH to be higher than seven. In the initial part of the curve, this is between 0-9ml of the base solution used, it is called the buffering region, in this region, the amount of strong base added is still not enough to neutralize completely the weak acid. The buffer solution achieves their resistance to pH change because of the presence of equilibrium between the acid (HCl) and its conjugate base (Cl-). The use of the phenolphthalein advertises when it reach an equivalence point, but it doesn´t give an exact quantity results, because when it turns into a purple color, the pH has already pass 7. ...read more.

Conclusion

In respect to the limitations, one of them is in the procedure, where the smash eggshell was mixed with the hydrochloric acid and then it was used directly for the titration. The problem with this was that in the solution, it formed some foam and there was some precipitation of some big pieces of the eggshell, so this it may cause some differences in the volume and concentration of the final solution after the titration. A way to solve this limitation is by making sure that the sample of the eggshell is smash completely, if necessary the use of a colander could be very useful, which will also help to have a more precise mass of the sample. The second part would be to filtrate the solution of the hydrochloric acid and the sample, to eliminate the foam and precipitation left, and then start the titration. ...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 ...

    � 100% = �0.24% (50.0�0.1)cm3 volumetric flask � 100% = �0.2% (10.00�0.05)cm3 pipette � 100% = �0.5% Total % uncertainty = 0.2 + 0.24 + 0.2 + 0.5 = �1.14% Total absolute uncertainty =� 0.4625 = �0.00527 moldm-3 (3 s.f)

  2. Calcium Carbonate and Hydrochloric Acid

    Data processing and presentation The results of both experiments are as follows: Fig. 1 Powder Fig. 2 Marble Chips Time (sec) Weight (g) Time (sec) Weight (g) 0 52,6484 30 52,5967 420 52,4304 60 52,5578 450 52,4283 90 52,5203 480 52,4257 120 52,4940 510 52,4228 150 52,4705 540 52,4195 180

  1. Determination of potassium hydrogen carbonate into potassium carbonate

    Therefore the total uncertainty can be calculated by summing up all the uncertainties that has been calculated. That is 1.7 + 0.9 = 2.6 % Therefore -0.282/0.0193 = - 14.619 KJ mol -1 � 6.6 % 2.6 + 4.0 = � 6.6 % The energy change for KHCO3 = (30/1000)

  2. Back Titration - Percentage Fertilizer

    This can be partially explained. It is important to note that the starting weight of Fertiliser used in each case was varied. This means that there was no opportunity for a "rough" titration because we would only do a titration for a particular weight once.

  1. How much calcium carbonate is in an eggshell

    This is no doubt the result of the formation of CO2 gas. Once this reaction was complete, NaOH was added to the solution to neutralize the acid and to enable calculation of the amount of acid used in the reaction.

  2. Calculate % of caco3 in white egg shell

    the contents of the flask to a 100 cm3 of measuring cylinder. Add more water to it till the final volume of the solution is 100 cm3. 3. Take in batches of 10.0 cm3 the solution and transfer it to a conical flask.

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

    of substance Z and finally, 3 times with 2.5g of substance Z. 15. All nine readings were recorded in the pre-made data tables. Safety Precautions: 1. Throughout the experiment, a lab coat was worn so that any spills do not cause damage to clothes or body.

  2. FInding the percentage purity of CACO3 in egg shell

    If the concentration of NaOH used due to inaccurate calculation is little then while titrating the burette will show great volume of NaOH that will be required to neutralize the acid hence an error, and if the concentration used is high then the burette will show a lower value of

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