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

Determine the concentration of limewater.

Extracts from this document...


To determine the concentration of limewater The aim of my experiment is to find the concentration of limewater solution in gdm. To do this, I am required to construct my own experiment and choosing reliable and appropriate apparatus. I will be provided with 250cm of limewater, which contains approximately 1gdm of calcium hydroxide. I also have hydrochloric acid, which has a concentration of 2.00-mol dm , which is too concentrated and will need diluting. Apparatus, equipment and chemicals Pipette 250cm Burette Conical flask 250cm Volumetric flask 250cm Graduated pipette Clamp + stand White tile Indicator (methyl orange) Limewater (250cm with 1gdm of calcium hydroxide) Hydrochloric acid (2.00-mol dm ) Distilled water Squeezing pump Balanced Equation In order to achieve limewater, dissolved slacked lime in water to get a solution of calcium hydroxide (Ca (OH) 2 ) Quicklime + water --------> slaked lime CaO (s) + H2O (l) --------> CaCl2 (aq) + 2H2O (l) In this reaction it shows the calcium oxide reacts with water to produce calcium hydroxide. After adding more water to calcium hydroxide, it produces the saturated aqueous solution known as limewater. Ca(OH) ...read more.


Because these are clear it means I can tell when the reaction has finished easier than using other indicators. Limewater, which is calcium hydroxide, is a strong alkali, even though it is only sparing soluble. Its pH is 14. Hydrochloric acid is a strong acid. This means that even if you have quite a weak concentration it completely dissociates in water into H3O+ ions and OH- ions giving a pH of 1 (The pH is a measure of how many hydrogen ions are present in solution). For the reaction of Calcium hydroxide and Hydrochloric acid I would use methyl orange. It changes colour at around pH 4.4 and will change from yellow in acid to pink in alkali by the addition of limewater. To make this experiment as accurate as possible, the pipette, burette and volumetric flask only have a percentage error of + or - 0.1%. This is only a small error. Also making sure the hydrochloric acid is poured into the burette carefully using a funnel will prevent the hydrochloric acid pouring down the side of the burette. Results I worked out the average titre like this: Mean = 13.2 + 13.3 + 13.2 / 3 = 13.2 Calculating the concentration of limewater Ca(OH) ...read more.


2. When you have filled the burette make sure that you have removed the air bubble from below the burette's tap. 3. When transferring the solution into the conical flask always use a graduated pipette. Ensure that the bottom of the meniscus is on the line. 4. Always leave the last drop in the graduated pipette - it is calibrated this way. 5. When adding indicator add only enough drops to get a reasonable colour. Too many drops will affect the end point and hence the accuracy of your results. 6. Always use a white tile so that the colour change at the end point is clear. 7. Before carrying out your first titration remove the filter funnel you used to fill the burette. 8. Record the starting volume and the final volume when the end point is reached. Don't forget to record the volumes to 2 decimal places - i.e. 0.00 means on the line 0.05 means between the lines. 9. Repeat the titrations until you get concordant results i.e. 2 identical titres or 3 within 0.1cm3 Another way I could have improved the experiment was if I was to use a larger quantity of limewater for the titrations and, as a whole would reduce the percentage error. Also by repeating the experiment several more times I could have obtained a better average result. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Aqueous 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 GCSE Aqueous Chemistry essays

  1. Free essay

    To determine the concentration of limewater

    5 star(s)

    moles of limewater / volume = 0.013 / 1 = 0.013 mol dm So there is 0.013 mole of Ca(OH) 2 per every 1000cm3 of solution. Therefore 25cm should contain 3.25x10-4 moles of Ca(OH) 2. 0.013/40=3.25x10-4 mole Ratio of limewater: Hydrochloric acid = 1: 2 = 3.25 x 10 :

  2. Find the concentration of limewater solution Titration

    In order to avoid these dangers as much as possible a lab coat and gloves must be worn. When not in use the chemicals should be stored in a sealed container in a fume cupboard. When the top is taken off the either of the bottles the ventilator must be turned on.

  1. titration of limewater

    250ml beaker, Wash Bottle (distilled water), White tile, Methyl Orange Indicator, Safety Goggles Method * Rinse all apparatus with distilled water. Then rinse the burette with Calcium Hydroxide and the pipette with Hydrochloric acid. This is to make sure the distilled water doesn't affect the concentration of the solutions and therefore make the experiment inaccurate.

  2. Determining the concentration of a limewater solution. This procedure will require a titration of ...

    that one mole of limewater reacts with two moles of hydrochloric acid. The limewater is approximately 1.00g dm-3 this is 0.0135mol dm-3 as the molecular weight of calcium hydroxide is 74 g dm-3 ? mr = mol dm-3 1.00 ?

  1. determining the concentration of a limewater solution

    Once each titration was complete I used litmus paper to check that the pH was neutral at pH7, this ensured that the correct amount of hydrochloric acid was being used to neutralise the limewater. It was also important to clean the conical flask in between each titre to make sure

  2. Plan. In this experiment I intend to discover the exact concentration of an unknown ...

    as it would take too little acid in order to neutralise the limewater (Ca(OH)2). If the values of the results are too small, the burette's accuracy is not sufficient to produce reliable results for the concentration of the limewater when calculated.

  1. Determine the concentration of lime water.

    The pipette that I was using was holding back some of the solution each time but I dispersed of this by blocking of the top end and wrapping my hand around the pipette, warming the interior slightly and pushing the drop out. Some errors are likely to come from measurements.

  2. The aim of this experiment is to determine as accurately as possible the concentration ...

    Collecting the washings off all the equipment used will ensure there are no Hydrochloric acid traces left, which could affect my results. These will be added to the volumetric flask, and continued to be filled with distilled water up to the 250cm3 line.

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