# Would the boiling point of water be higher or lower on the top of a mountain peak? How would the boiling point be affected in a pressurized boiler system?

The boiling point of a liquid is the temperature at which the vapour pressure of the liquid is equal to the ambient pressure, and bubbles of vapour form directly in the liquid. The $\text{normal boiling point}$ is specified when the ambient pressure is $\text{1 atmosphere}$.
So, if the ambient pressure is reduced, the boiling point of a liquid should also be reduced. This is the principle behind vacuum distillation, when an otherwise involatile liquid is distilled under (greatly) reduced pressure. The boiling point of water in Denver, Colorado, is $90$ ""^@C. Why so?