Question

Benzene is a starting material in the synthesis of nylon fibers and polystyrene (styrofoam). Its specific heat capacity is 1.74 J/(g·K).
If 16.7 kJ of energy is absorbed by a 225-g sample of benzene at 20.0°C, what is its final temperature?

A) -22.7° C
B) 36.7° C
C) 42.7° C
D) 62.7° C

Answer 1

Answer:

D

Explanation:

The amount of energy released or absorbed is equal the product of the mass, the specific heat capacity and the temperature change. The temperature change being the difference between the final and initial temperature.

Q = mc∆T

Q = heat energy (Joules, J) m = mass of a substance (kg) c = specific heat (units J/g∙K)

∆ is a symbol meaning "the change in" ∆T = change in temperature (Kelvins, K)

From the data provided in the question, we can deduce that:

Q = 16.7KJ = 16,700J

m = 225g

c = 1.74J/g.k

For the temperature, let the final temperature be f. This means our ∆T = f - 20

16,700 = 225 * 1.74 * (f - 20)

16700 = 391.5 (f - 20)

f - 20 = 16700/391.5

f - 20 = 42.7

f = 20 + 42.7 = 62.7

Hence the final temperature is 62.7 degrees Celsius