Question

A chemist carefully measures the amount of heat needed to raise the temperature of a 0.47 kg sample of C6H7N from 30.5 degrees C to 48.4 degrees C. The experiment shows that 1.65 x 10^4 J of heat are needed. What can the chemist report for the molar heat capacity of C6H7N? Be sure your answer has the correct number of significant digits.

Answer 1

Answer:

Mass of the sample = m = 894.0 g

Initial temperature of the sample = T_i=-5.8^oC=267.35 KT

i

=−5.8

o

C=267.35K

Final temperature of the sample = T_f=17.5^oC=290.65 KT

f

=17.5

o

C=290.65K

Change in temperature = \Delta T=(T_f-T_i)ΔT=(T

f

−T

i

)

Specific heat capacity of the substance = c

Heat required to raise the temperature of a 894.0g sample = Q

Q = 4.90kJ = 4900 J

Q=m\times c\times \Delta T=m\times c\times (T_f-T_i)Q=m×c×ΔT=m×c×(T

f

−T

i

)

4900 J=894.0 g\times c\times (290.65 K-267.35 K)4900J=894.0g×c×(290.65K−267.35K)

c=0.23523 J/g K\approx 0.235 J/g Kc=0.23523J/gK≈0.235J/gK

The chemist will report the specific heat capacity of the substance as 0.235 J/g K.