Question

How much energy in kilojoules is released when 23.4 g of ethanol vapor at 83.0 ∘C is cooled to -15.0 ∘C ?

Answer 1

Answer : The amount of in kilojoules released is, -5.53 kJ

Explanation :

Formula used :

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat released = ?

c = specific heat of ethanol = $2.41J/g^oC$

m = mass of ethanol = 23.4 g

$T_{final}$ = final temperature = $-15.0^oC$

$T_{initial}$ = initial temperature = $83.0^oC$

Now put all the given values in the above formula, we get:

$q=23.4g\times 2.41J/g^oC\times (-15.0-83.0)^oC$

$q=-5526.612J=-5.53\times 10^3J=-5.53kJ$

Therefore, the amount of in kilojoules released is, -5.53 kJ