Titration

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1.6.2 Sources of errors

Random

Suggestion to reduce the errors

Measurement of sodium hydroxide solution. Parallax error occurred when we want to read the meniscus level as the pipette is very long in height.

Take a stool in order to reach to the level of meniscus efficiently.

Measurement of orange juice by the electronic balance are varied.

The measurement obtained are differed with one and another even though has the same volume.

Make sure that the electronic balance is calibrated first to prevent zero error

The dropping of the sodium hydroxide solution drops into the conical flask is inconsistent and hard to handle

Make sure the task for handling the dropper is assigned by only one person to prevent any misleading and increase the focus

Systematic

Suggestion to reduce the errors

Contamination of the rubber bulb.

The water accidentally risen up to the rubber bulb might contaminated from the inside dirt.

Be sure that we press the correct place to press which labelled ‘E’ to excrete the water out not the labelled ‘S’ which is to suck in.

1.6.3 Evaluation of the experiment for precision and accuracy

Precision

As a whole, the results obtained has slightly off the precision. However, the measurement for the second and third conical flask are high in precision.

Accuracy

From my observation, our data collection are not highly accurate as for the errors presences. But, we can take the second and third data of conical flask to find the average.

1.6.4 Suggestion of improvements for the experiments

Glass wares

Make sure all glass wares are rinse off with their suitable solution to prevent any error.

Reading

Our eyes should be the same level as the meniscus level so that we could increase the accuracy of data.

Decision and focus

The time when doing the dropping process into the conical flask has been quite challenge. To do so, please only one person make the judgement when to stop and the

Data collection of experiments

The data collection for the experiments must be taken for 3 or more attempts in order to get the average of data. The experiments must be repeated in order to get a better result of the data obtained.

1.8 Review on teamwork

[pic 16]

This is my third chemistry lab report done with my partner, Janariah Reza. I am blessed to have her as a team in conducting the complicated experiment. We had completed every steps of the procedures with both sides cooperation as this experiment needs critical handling.

We assigned the task equally based on our specialities. Most of the apparatus set up was done by me as I’m more careful while she’s the one who observing and collecting data as she is more expert and aware of the chemical changes. The photographs captured were hard to be taken as we need all four hands throughout the experiments. However, we managed to get few of the important photos of data.

In addition, before we start the experiment we consult with our lecturer to prevent any misleading in the procedures taken. This is very essential as one mistake could lead us to disaster and we might have to repeat our experiments in getting a better results. To sum up, this experiment has taught us to be patience and critical despite the complexity experienced throughout the experiment.

1.9 Conclusion

The data obtained was satisfied as we got the 0.1mL gap between the attempts which means high precision. The average percentage of citric acid in the 20mL of orange juice was calculated based on the second and third attempts as the result were the most precise. The final result of citric acid in the orange juice obtained is 0.1186 %.