Hello, did you know whether the deltaU= Q- W is valid in solving the change in internal energy in isochoric or not?

Yes because water vapour [H2O](g)is a polyatomic gas

@@siyakubongafortune5470 noted with thanks

Units! There's 0.08206 L·atm/K·mol and 8.314 J/K·mol. In the PV=nRT formula you use the 0.08206 L·atm/K·mol and the units will cancel to leave you with what you're solving for. In this case T so you'll be left with K. Try the formula with the units and cancel them out. pretty helpful trick i think

@@nahnahnah30 are there other units of R other than that? Like to english units like btu and rankine

​​@@nahnahnah30n solving the internal energy using Cv = 5/2 (R), should it always be 8.3145, will it not affect the equation even if the givens are in Liters and atm? Thank you in advance for ur reply

Hi

It depends on the units of pressure Temperature

Pressure volume temperature

Depends on the unit is 8.31 for Pa and m^3 however when working with litres ant atm(atmospheric pressure) we use 0.08206

He should have used 0.08206 as R since the pressure is at ATM and Volume is in Litres ....R is always 8.3145J when the pressure is in Pascal and volume is in Cm³

Zoe Reed it’s 5/2 for a diatomic gas 3/2 for a monoatomic