Answer:
C nhé ! CH3COOH là axit chứ không phải este
The correct option is A.
In scientific investigation, variable refers to those parameters that are manipulated or changed in an experiment. Variables are those factors or conditions that can exist in different amounts in a scientific investigation. There are three major types of experimental variables, these are, independent, dependent and controlled variables. All the variables that are used in an experiment are usually connected to one another, scientific investigators typically look for the relationships among the variables in order to depict how they associate with one another.
I believe the compound KOI is meant to be potassium iodate, which is KIO₃. This compound will also be the one with the highest melting point.
This is due to the fact that potassium ion will form ionic bonds with whatever atom or molecule it binds to. Ionic bonds involve the complete transfer of electrons, making them very strong and hard to break, meaning the compound will have the highest melting point.