# fancy entropy exercise?help needed

• Oct 27th 2007, 03:52 AM
marikas
fancy entropy exercise?help needed
3. The entropy change, ΔS, associated with the isothermal (i.e.
constant temperature) change in volume of n moles of an ideal
gas from volume V1 to volume V2 is given by the equation
ΔS = nR ln(V2/V1)
where R is the gas constant.
(a) If a compression occurs (V2 < V1) use Equation 1 to deduce
whether there will there be an increase ( ΔS is positive) or
decrease ( ΔS is negative) in the entropy of the gas.
Section 2: Coursework 12
(b) If an expansion occurs (V2 > V1) use Equation 1 to deduce
whether there will there be an increase or decrease in the
entropy of the gas.
(c) The ideal gas law states that pV = nRT, where p is the
pressure of the gas. Use this expression and Equation 1 to
obtain an equation relating the entropy change to the initial
and final pressures (p1 and p2). (Note that n,R and T will
be constant at the two different pressures).
• Oct 27th 2007, 04:50 AM
Soroban
Hello, marikas!

Who told you to format like this?

Quote:

[COLOR=black ][ /COLOR ] [COLOR=black ][/COLOR ]
What was that for? .black-On, black-OFF ?

[FONT=Times New Roman ][COLOR=black ][FONT=CMR10 ]
Why declare a font if you're going to change it before you use it?

3. The entropy change, [/FONT ] [/COLOR ][COLOR=black ]Δ[/COLOR ][COLOR=black ][FONT=CMMI10 ]S[/FONT ][/COLOR ]
Once you declare "[COLOR=black ]" it stays in black until you change it.
You don't have to do black-ON, black-OFF for every font-change.

If you want italics, don't change fonts.
. . Just use $\displaystyle \text{[i]}$ and $\displaystyle [/\text{i}]$