Potassium Hydroxide Experiment

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The initial hypothesis that was made regarding the strength of the solid compounds was supported with this experiment. The hypothesis stated that potassium hydroxide would have the greatest effect on the acidic solution. This was supported here as it had the highest average change in pH by far. On average, the pH value of the acidic solution increased by 12.5. This is significantly higher than the increase of the other solutions, which only increased around a pH of 4. The reason why potassium hydroxide seemed to be the strongest alkaline-forming substance is because it is considered a strong base. Meaning that it is able to remove a H+ ion off an acidic solution. In this case, once potassium hydroxide was added into the 1mL of nitric acid in …show more content…
This can be explained as its original pH was quite basic. It is a salt of a strong base and therefore, it was able to raise the pH of the solution exponentially. However, it does not fully act as a base. This is shown when the product contained some solid material at the bottom of the beaker. This means that the solid compound was unable to disassociate fully. The same thing occurred for zinc oxide. As zinc oxide is not a strong base, it was unable to fully dissociate in the highly strong nitric acid. It is not a strong base as it is an amphoteric oxide that works as both an acid or a base. Thus, the reaction resulted in the production of a murky coloured liquid. If a full neutralization reaction was to completed, a product of a transparent solution should have been created. Sodium phosphate and potassium sodium tartrate are both not strong bases and that is why the average pH change was quite low. Both of them are not bases, however, they have a high pH. This is why they were both able to increase the pH on the acidic solution. A neutralization reaction did not occur, and that is why the solutions were not transparent, but rather murky like the other weaker base …show more content…
The pH meter for example, was a common disturbance in the data. Although the same meter was used for all of the trials (to ensure that a potential difference in meters did not affect the data), many of the meters that were available for the lab were quite faulty. Even after it was calibrated, they seemed to jump around in values until finally reaching one value. Although it seemed to work fine for consecutive trials, the meter would eventually require another calibration. This occured for all of the meters that were tested (all meters were tested to see which one could work the best before the trials began). The pH meter may also have been a problem throughout the original experiment. In order to fix that, pH strips may have provided a more accurate measurement. Although pH strips are not very precise, they offer an accurate measurement in the area of the exact pH. Thus by using these strips, the pH data could have been more accurate. Another potential error that could have occured in this lab was the amount of stirring that was performed during the trials. There is no way to regulate how much stirring each trial experienced and thus, it could potentially become a source of error. This is because if more stirring occured, in the 60 second time limit, more of the solid compound could have dissolved, changing

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