Answer
(a) decrease
(b) $662J/K$
(c) increase
Work Step by Step
(a) It is given that a small dish of water is placed outside for birds and at night the temperature drops to $-5.0^{\circ}$. Thus, the heat flows out of water and as a result the entropy of the system decreases.
(b) We know that
$\Delta S=\frac{Q}{T}$
We plug in the known values to obtain:
$\Delta S=\frac{mL_f}{T}$
We plug in the known values to obtain:
$\Delta S=\frac{(0.53Kg)(33.5\times 10^4J/Kg)}{268K}$
$\Delta S=662J/K$
(c) We know that the entropy increases whenever heat is added to the system.