It takes 330 joules of energy to raise the temperature of 24.6 g of benzene from 21 degrees Celsius to 28.7 degrees Celsius at constantpressure. What is the molar hear capacity of benzene at constantpressure?

Molar heat capacity C = 136.09 JK-1mole-1

Explanation:

Heat capacity,  C = Q/ ΔT

where C = heat capacity

Q =heat energy=  Q = 330 J

ΔT is temperature difference =Change in temp =

ΔT = (28.7  +273)-( 21 + 273)= 7.7 K

But

No. of moles of benzene= mass / molar mass

  = 24.6g / 78.11g/mol

     = 0.3149 moles

Molar heat capacity C = Q/ nΔT

                             = 330 / ( 0.3149 x 7.7 )

                             = 136.09 JK-1mole-1

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml