Question
Q71. Water can dissolve more substances than any other liquid because
a) It is dipolar in nature
b) It is a good conductor of heat
c) It has high value of specific heat
d) It is an oxide of hydrogen
Answer: A
Detailed Explanation
Water is called the universal solvent because it is capable of dissolving more substances than any other liquid. Water can dissolve more substances than any other liquid because it is dipolar. Hence, Option A is correct.
Water molecules have a polar arrangement of oxygen and hydrogen atoms — one side (hydrogen) has a positive electrical charge and the other side (oxygen) had a negative charge.
This allows the water molecule to become attracted to many other different types of molecules.
Water can become so heavily attracted to a different compound, like salt (NaCl), that it can disrupt the attractive forces that hold the sodium and chloride in the salt compound together and, thus, dissolve it.
Because of its polarity, water can form electrostatic interactions (charge-based attractions) with other polar molecules and ions.
Extra:
The polar molecules and ions interact with the partially positive and partially negative ends of water, with positive charges attracting negative charges (just like the + and – ends of magnets).
When there are many water molecules relative to solute molecules, as in an aqueous solution, these interactions lead to the formation of a three-dimensional sphere of water molecules, or hydration shell, around the solute.
Hydration shells allow particles to be dispersed (spread out) evenly in water.
Nonpolar molecules, like fats and oils, don’t interact with water or form hydration shells.
These molecules don’t have regions of a partial positive or partial negative charge, so they aren’t electrostatically attracted to water molecules.
Thus, rather than dissolving, nonpolar substances (such as oils) stay separate and form layers or droplets when added to water.
