I need help with this

Question

In a 4.00 L pressure cooker, water is brought to a boil. If the final temperature is 115 Celsius at 4.70 ATM, how many moles of steam are there in the cooker

Answer 1

Hello, Yesenvia,

I went through this quickly, so please check my steps carefully.

I'll assume that there is no liquid water in the pressure cooker. To be certain, one should check the phase diagram for water under the temperature and pressure conditions used here. I looked quickly, and it seems that these conditions would result in no liquid water, so we'll assume everything is in the fas phase.

The ideal gas law is used to calculate the number of moles, n. PV = nRT. Temperature must be in Kelvin and I picked a gas constant that had compatible units (R = 0.0821 (L atm)/(K mole)). I calculate 0.59 moles of water.

Bob