Answer
$\Delta S_{copper}=-27.1\frac{J}{K}$
Work Step by Step
We know that:
$\Delta S_{copper}=\int_{353}^{314}\frac{cm dT}{T}$
where $40.9^{\circ}C=314K$ and $80.0^{\circ}C=353$K
The above equation can be written as:
$\Delta S_{copper}=cm\ln(\frac{T_f}{T_i})$
We plug in the known values to obtain:
$\Delta S_{copper}=386(0.600)\ln(\frac{314}{353})=-27.1\frac{J}{K}$
