[vanklik]

In one of the problems I've calculated the mass of water that the mountaineers could boil using the remaining gas. I need to explain the reasons why, in practice, they would only be able to boil about half this mass of water.

I think there will be a big loss of heat to surroundings, also at high altitudes, the lower air pressure means incomplete combustion therefore less energy than expected.

Is this correct? Is there any other reasons?

Thank you!

[Mitch]

They would be able to boil more water than the same amount at sea level. I would think this because the boiling point for water will be lower than 100 C at the top of a mountain.