Question

Thermodynamic Properties

Property Value
c (solid) 0.5 J/g °C
c (liquid) 1.0 J/g °C
c (gas) 2.0 J/g °C
Melting Point −114 °C
Boiling Point 78 °C


How much heat is released when 60.0 g of ethanol cools from 70 °C to 43 °C?

Answer 1

its 1600 J

Step-by-step explanation:

i just got it right on the quiz

Answer 2

1,620 J.

Step-by-step explanation:

• The amount of heat added to a substance (Q) can be calculated from the relation:

Q = m.c.ΔT.

where, Q is the amount of heat released from ethanol cooling,

m is the mass of ethanol (m = 60.0 g),

c is the specific heat of ethanol in the liquid phase, since the T is cooled below the boiling point and above the melting point (c = 1.0 J/g °C),

ΔT is the temperature difference (final T - initial T) (ΔT = 43.0 °C – 70.0 °C = - 27.0 °C).

∴ Q = m.c.ΔT = (60.0 g)(1.0 J/g °C)(- 27.0 °C) = - 1620 J.

• The system releases 1620 J.