Question

Assertion :Water boils below 100${}^{\circ }$C on top of Mount Everest. Reason: Greater the pressure, the higher the boiling point.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct, but Reason is not the correct explanation for Assertion.
• C. Assertion is correct, but Reason is incorrect.
• D. Assertion is incorrect, but Reason is correct.

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

Boiling point is the temperature at which the pressure exerted by the surroundings/atmosphere upon a liquid is equal to the pressure exerted by the vapours of the liquid. At elevations/high altitudes like Mount Everest, the atmospheric pressure is low (less than 1 atm), hence a lower vapour pressure of water is required to reach its boiling point. This will result in lowering of boiling point of water from 100${}^{\circ }$C at 1 atm. Thus lower the pressure lower is the boiling point or vice-versa.

Therefore, Assertion and reason are correct and correlated

option A is correct