Practical Assessment Task 3: Preparation

evaluation part 1: fair test

My test was a fair test to a high degree. My hypothesis stated that when the Aspro Clear tablet is placed in 100 millilitres of tap water, it will dissolve faster than when the Aspro Clear tablet is placed in 100 millilitres of vinegar. This hypothesis had a clear dependent variable (the dissolution rate) and an independent variable (the solvent the Aspro Clear tablet dissolves in).) It also had clear controlled variables including the quantity of the liquid placed into each beaker (100mL) and the brand of the tablet used (Aspro Clear).

Evaluation part 2: fair test

 This ensured that only the solvent the Aspro Clear tablet dissolved in (independent variable) was changed so that only the time taken for the Aspro Clear Tablet to dissolve (dependent variable) was measured. This allowed the hypothesis in the experiment to be effectively tested.

evaluation part 3: accuracy

There was a moderate degree of accuracy in the experiment. The experiment was able to be accurate to some extent through the use of the stopwatch, which prevented bias in the results. Additionally, by mainly using glass equipment and deviating from using metal equipment, it prevented any additional reactions from occurring since glass does not react with acid. This also increased accuracy.

evaluation part 4: accuracy

Despite this, the systematic error of using a plastic pipette to measure the 100mL that went into each beaker limited the accuracy as this equipment does not provide an exact value, unlike their measuring cylinder counterpart. This meant that the 100 mL of liquid placed into each beaker may have not exactly been 100mL. The cloudiness of the vinegar when the Aspro Clear tablet was placed into it made it difficult to distinguish where the tablet was in the mixture at times and whether or not it was completely dissolved. This random error also had a negative impact on the experiment’s overall accuracy.

evaluation part 5: reliability

Although there was consistency across all conducted trials, I was still unable to conclude whether there was reliability or not because the two trials conducted provided too small of a sample size. 

Evaluation part 6: concluding sentence

Overall, while the experiment was a fair test, and was accurate to a moderate degree, it still was not valid because of the lack of reliability and issues with its accuracy.