Question

Why should we always use a water bath while boiling the leaf in an alcohol solution?

Answer 1

Hint: To solve this question, we must first understand the physical properties of alcohol as well as water. Then we must compare the values of these physical properties to reach a conclusion for this question.

Complete Step-by-Step Answer:
Before we move forward with the solution of the given question, let us first understand some important basic concepts.
Now, in the case of molecules containing hydrogen atoms and which exhibit some polar character, a special type of dipole – dipole interaction is observed. Thus, forms of inter – molecular interaction are known as hydrogen bonding. In hydrogen bonding, the terminal hydrogen atom of the polar molecule (which is the positive end) tends to attract to the negative end of another molecule in the substance. This creates a form of pseudo bonding known as hydrogen bonding. The degree of strength of this hydrogen bonding is dependent on the polar character of the molecules.
The alcohol used in the experiment where we boil a leaf in it, is often ethyl alcohol. The polar character of a molecule of ethyl alcohol is lower than a molecule of water. Because of this reason, the boiling point of water is higher than ethyl alcohol. Also, ethyl alcohol is highly flammable, and directly heating it would cause it to catch fire.
Hence, in order to not let our experimental set up catch fire, we always use a water bath while boiling the leaf in an alcohol solution

Note: Polarisation in a molecule can be explained as the creation of a dipole within a molecule. This dipole is formed due to the difference in electronegativity of the constituting atoms. The more electronegative atom tends to pull the bonding electron cloud towards itself to create a shift in charge within the molecule. This shift in charge is responsible for the formation of the dipole.