(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 

Ans: a

Explanation:

It is water’s chemical composition and physical attributes that make it such an excellent solvent. 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 i.e. the dipolar nature of water molecules. This allows the water molecule to become attracted to many other different types of inorganic 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.

Unique features of Water:

1. It exists as a liquid over a wide range of temperature i.e from 0⁰ to 100⁰C.
2. It has the highest specific heat, due to which it warms up and cools down very slowly without causing shocks of temperature jerks to the aquatic life.
3. It has a high latent heat of vaporisation. Hence, it takes a huge amount of energy for getting vaporised. That’s why it produces a cooling effect as it evaporates.
4. It is an excellent solvent for several nutrients. Thus, it can serve as a very good carrier of nutrients, including oxygen, which are essential to life. But, it can also easily dissolve various pollutants and become a carrier of pathogenic microorganisms.
5. Due to high surface tension and cohesion it can easily rise through great heights through the trunk even in the tallest of the trees like Sequoia.
6. It has an anomalous expansion behaviour i.e as it freezes, it expands instead of contracting and thus becomes lighter. It is because of this property that even in the extreme cold, the lakes freeze only on the surface. Being lighter the ice keeps floating whereas the bottom waters remain at a higher temperature and therefore, can sustain aquatic organisms even in extreme cold.

Hence, option a is correct.

Read: Solved PYQs Science & Technology With Explanation 2021 UPSC Prelims