How much heat must be absorbed by 125 g of ethanol to change its temperature from 21.5 ∘C to 34.8 ∘C? (Specific heat capacity of ethanol is 2.42 J/g∘C)

a. 86.6 kJ
b. 4.02×103kJ
c. 6.95 kJ
d. 4.02 kJ

Respuesta :

Answer:

Option D. 4.02 kJ

Explanation:

A simple calorimetry problem

Q = m . C . ΔT

ΔT = Final T° - Initial T°

C = Specific heat capacity

m = mass

Let's replace the data

Q = 125 g . 2.42 J/g∘C . (34.8°C -21.5 °C)

Q= 4023.25 J

We must convert the answer to kJ

4023.25 J . 1kJ /1000 =4.02kJ