Lowering the atmospheric pressure on a liquid
[amp_mcq option1=”increases the boiling point of the liquid” option2=”lowers the boiling point of the liquid” option3=”does not affect the boiling point of the liquid” option4=”increases the time required for it to boil” correct=”option2″]
This question was previously asked in
UPSC CAPF – 2018
The correct answer is B) lowers the boiling point of the liquid.
Boiling point is defined as the temperature at which the vapor pressure of a liquid equals the surrounding atmospheric pressure. When the atmospheric pressure is lowered, the liquid needs to reach a lower vapor pressure to start boiling. Since vapor pressure increases with temperature, a lower required vapor pressure is achieved at a lower temperature. Therefore, lowering the atmospheric pressure on a liquid lowers its boiling point.