Question
Question: Unusually high boiling point of water is result of: A. Intermolecular hydrogen bonding B. Intram...
Unusually high boiling point of water is result of:
A. Intermolecular hydrogen bonding
B. Intramolecular hydrogen bonding
C. Both intra and inter molecular hydrogen bonding
D. High specific heat
Solution
When the vapor pressure of water is the same as that of the atmospheric pressure of the water, the temperature at this point is called boiling point of water. We know that when water is boiled, it is turned to vapor state.
Complete answer:
Boiling point of water is due to the presence of hydrogen bonding. Hydrogen bonding is the attraction between the positive end and negative end of the molecules. This occurs in polar molecules. This attraction is called dipole-dipole attraction.
We also know that the pressure of water affects the boiling point of water. When the pressure is increased, the boiling point is increased, i.e. the liquid has a higher boiling point when it has high pressure.
The structure of water is given below:
Water has a bent shape. It has two hydrogen atoms and one oxygen atom. There is a partial positive charge on hydrogen atom and a partial negative charge on the oxygen atom. There is a force of electrostatic attraction between them. The atom, which is more electronegative, is bonded to another atom, which is less electronegative than the first atom. This makes the hydrogen bond. There occurs multiple hydrogen bonds in water molecules.
Thus there is an intermolecular hydrogen bonding between water molecules.
Hence, the correct option is A.
Note:
There does not occur an intramolecular hydrogen bonding. Intramolecular hydrogen bonding is the hydrogen bonding in the same water molecule. While intermolecular hydrogen bonding is between two water molecules. Hydrogen bonding occurs due to several factors like surface tension, vaporization energy and specific heat.