According to the chart, the period and string length are not the same. Regardless of string length. The chart says that "period = seconds 10"
Explanation:
So for example in Trial 1. The period equaled 8.7, so in turn you would times 8.7 by 10 and get 87. Which is not equal to the string length. For they are also measured in two different measurements.
The answer is (2). The question only ask the production of acid reacts with base. The acid has H+ ion and base has OH- ion. When they react, the production will always contain H2O.
