AS Chemistry Coursework: Titration Essay Example

ofthe volumetric flask withdistilled wate rto ensure no more solu tion remains onthesides.Finally fillapipette with th esolution andtransfer25 cm ^ t hree

When filling the pipette, it is recommended to remove the pipette filler. Releasing solution with your thumb will provide better control over measurements. To ensure accuracy, invert the pipette to remove bubbles in the tip and mix the solution evenly. When transferring into a conical flask, place the tip on the floor of the flask without touching the sides. It is normal for some solution to remain in the tip after emptying, so there's no need to completely empty it. Next, set up a burette in a clamp with space below for the conical flask. Flush acid through beforehand to eliminate any substances that may affect results. Use a funnel when transferring acid into the burette to prevent spillage, pouring below eye level as a safety precaution. Stop filling just before reaching the calibration mark and use a 5cm pipette to add final drops up to that mark. Keep your eyes horizontal with it and hold white paper behind for clear visibility of both mark and meniscus. Make sure to note down start point for reference.

To evenly mix the alkali solution, add 3 drops of methyl orange and swirl. Place a white tile under the conical flask to make it easier to see the end point. Perform a test titre before starting the actual tests to estimate when the alkali will be used up. This allows for more accurate testing near that point. To perform the titre, open the valve on the burette and let acid flow into the flask.

Continuously swirl to mix and neutralize between the alkali and acid. Gradually slow down near the estimated point during actual testing. Use droplets from the burette and look for a permanent color change while swirling. Each droplet represents 0.5ml.

After conducting the rough titration, it should be repeated until at least 2 concordant results have been obtained. To repeat the process, rinse the conical flask with distilled water or use a new one, and add more alkali solution along with 3 additional drops of indicator. Refill the burette with more acid if there is insufficient amount for the titration, taking note of the starting point.

The results of the rough titrations are as follows:
Initial Burette reading/cm: 0.00
Final Burette reading/cm ACID: 25.05

The accurate titrations yielded the following results:
Initial Burette reading/cm: 0.00
Final Burette reading/cm: 25.15
Initial Burette reading/cm: 0.00
Final Burette reading/cm: 25.10
Initial Burette reading/cm: 0.00
Final Burette reading/cm: 25.20.

Analysis:

The average calculation of my concordant titration results (which are the only results in this case) is 25.15cm (25.15 + 25.10 + 25.20 =75 .45 /3 =

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Answer:

According to;"3 Moles = Concentration x Volume," for;the Na?CO? solution,;the moles equal to;0.;1 in;1dm?.

In 1 cc (1 x 10-3 dm), there is .0001 moles. In 25cm, there is 0.0025mol. This required 25.15 cm3 of acid to neutralise it, so this volume also contained .0025 moles. Concentration = moles Volume = .00025 25.15x 1 x 10-3. Evaluation: There are several errors that may have influenced my results.