Boiling Point of a Liquid

[Heather Lindsay 1H]

How does altitude/difference in pressure affect the boiling point of a liquid? Is the boiling point of a liquid higher at a lower altitude? If so, why is this true?

[Annie Qing 2F]

Yes, the boiling point of a liquid is higher at a lower altitude/higher atmospheric pressure.
The boiling point is defined as "the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor." As you decrease altitude, the atmospheric pressure gets higher, so the vapor pressure needs to be higher to equal the pressure surrounding the liquid. Thus, the boiling point is also higher.

Hope this answers your question somewhat?