Question

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?

Answer 1

J= (12)(1.8)(2.5)

J=54

Answer 2

Answer:

-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.