2010-10-14, 10:32 PM
In calculus, I learned that if z=xy, then z'=xy'+x'y. However, in my chemistry class, I was given this following equation and told to memorize it:
dW = -PdV
I wanted to know where this comes from, so I did some searching, and after searching it for a while, I was unable to find the answer anywhere. Where is the VdP part of the equation? And why is there a negative sign? Should VdP also be negative so that the differential equation can be integrated? (into W=-PV)
I know that this is probably a partial derivative, but I came across nothing that states why this equation must be taken as a partial derivative. Actually, I couldn't find anything other than Wikipedia that denoted it as a partial.
What if you had a pressure change but not a volume change? I'm confused.
dW = -PdV
I wanted to know where this comes from, so I did some searching, and after searching it for a while, I was unable to find the answer anywhere. Where is the VdP part of the equation? And why is there a negative sign? Should VdP also be negative so that the differential equation can be integrated? (into W=-PV)
I know that this is probably a partial derivative, but I came across nothing that states why this equation must be taken as a partial derivative. Actually, I couldn't find anything other than Wikipedia that denoted it as a partial.
What if you had a pressure change but not a volume change? I'm confused.