the metal was moving in the direction the gas was pushing. That is positive work.
As for the first part, figure out how many mols of water vapor you have and how many mols of air, Then do PV = nRT to get partial pressures of each. That final pressure inside is ten times atmospheric plus 1 atm.
I once was given a metal whiskey flask for being in my cousin’s wedding. When it got dented, I put in 1 gram of H2O (initially 21°C, just like the air filling the rest of the flask) and heated it up to boil the water. It popped the dent out.
Assume the flask had a rectangular cross section, with a height of 15 cm, a width of 10 cm, and a thickness of 2 cm. Assume that in order to pop the dent out, an outward pressure difference of 1.0E6 Pa was required (that is, the outward pressure on the flask minus the inward pressure on the flask was 1.0E6 Pa). How much heat had to be added to the contents of the flask?
At the instant the dent popped out, was the gas inside the flask doing positive work, or was positive work being done to the gas?
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