Answer:
Q (heat) = S * m * (T2 - T1) where Q is heat gained (loss), S the specific heat capacity of the substance and T2, T1 are the final and initial temps
Q = .215 cal / (g deg C) * 5 g * (20 - 80) deg C = -64.5 cal
Since the question specifies the heat emitted, then 64.5 cal is the
heat emitted (loss).