Ethanol has heat specific heat of 2.5 j/g⋅°c, how much heat is released when 12 g of ethanol is cooled from 38.5 °c to 36.7 °c?

-54 J

Explanation:

Here we have to use the specific heat equation,

Q = mc∆T

where Q is the heat, m is the mass, c is the specific heat capacity and ∆T is the change of temperature.

Given,

m = 12 g

c = 2.5 J/g⋅°C

∆T = Tfinal - Tinitial = 36.7 °C - 38.5 °C = - 1.8 °C

Plugging the numbers in the specific heat equation,

Q = 12 g x 2.5 J/g⋅°C x - 1.8 °C = - 54 J

As heat is released Q has a negative sign. When heat is absorbed Q has a positive sign.

J = (12) (1.8) (2.5)

J=54