Two months of summer vacation quietly flew by and a fresh school year has arrived. In the second week of the new semester, the grade 12 students had their first experiment in chemistry class, which was to investigate ways t control the oxidation speed of apples. The seemingly professional experiment was actually based on a small example from our daily life — when we eat an apple, if we don’t finish it and put it aside, the pulp of the apple will start browning after a while, and the taste will not be as good as before.
The chemistry teacher, Mr. C, gave students four methods: dipping apple slice in water, in lemon juice, putting it in refrigerator and in sealable bag. According these methods, all the students were divided into groups and made their own guesses. Some students thought that apple slices dipped in lemon juice would be the slowest to oxidize, because lemon juice is an inhibitor of oxidation reaction. However, some students disagreed with the idea that when apple slices were put in sealable bags and oxygen was completely pressed out, it was the best way to slow down the oxidation.
All the hypotheses need the support of the experimental results. In the chemistry class, the students actively photographed and recorded the color changes of each apple slice. After class, they also discussed the differences of the experimental results between groups and the possible errors of the experiments.
Through this little experiment, we learned that everything around us is worth exploring. Even a little thing like eating apples, may contain a huge secret.
by Elaine Bao (Grade 12)