Thread: helpppp please. nobody can solve it??

this has been solved now

Originally Posted by marikas

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.

Hello,

$\displaystyle \Delta S=n \cdot R \cdot \ln \left(\frac{V_2}{V_1}\right)$

If $\displaystyle V_2 < V_1$ then $\displaystyle \frac{V_2}{V_1} < 1$ and then $\displaystyle \ln \left(\frac{V_2}{V_1}\right)<0$ that means negative and therefore the complete product is negative too. Thus $\displaystyle \Delta S$ is negative so there is a decrease in the entropy of the gas.