Answer :
The question is: You have 500g of ethyl alcohol at a temperature of -40 ° C. How much heat is needed to transform it into steam at a temperature of 150ºC?
Answer: 233700 J heat is needed to transform ethyl alcohol into steam at a temperature of [tex]-40^{o}C[/tex] to [tex]150^{o}C[/tex].
Explanation:
Given: Mass = 500 g
Initial temperature = [tex]-40^{o}C[/tex]
Final temperature = [tex]150^{o}C[/tex]
The standard value of specific heat of ethyl alcohol is [tex]2.46 J/g ^{o}C[/tex].
Formula used to calculate the heat energy is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass of substance
C = specific heat
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\= 500 g \times 2.46 J/g^{o}C \times [150 - (-40)]^{o}C\\= 233700 J[/tex]
Thus, we can conclude that 233700 J heat is needed to transform ethyl alcohol into steam at a temperature of [tex]-40^{o}C[/tex] to [tex]150^{o}C[/tex].