Answer:
4590 joules
Explanation:
First of all, you need to know the specific heat (C) of the isopropyl alcohol which has the value of 3 kJ /kg°C.
This is an easy calorimetry problem. The formula is Q = m . C . ΔT.
Where m is the mass of compound and ΔT the difference of T°
ΔT = Final T° - Initial T°
Let's replace data, and firstly, we convert the mass of alcohol from g to kg, because the units of the Specific heat
25 g . 1kg /1000g = 0.025kg
Q = 0.025 kg . 3 kJ/kg°C (82.4°C - 21.2°C)
Q = 4.59 kJ
If we want the value in joules, we make the conversion:
4.59 kJ . 1000 J/ kJ = 4590 J
