Respuesta :
Answer: The amount of heat required for melting of benzene is 20.38 kJ
Explanation:
The processes involved in the given problem are:
[tex]1.)C_6H_6(s)(5.5^oC)\rightleftharpoons C_6H_6(l)(5.5^oC)\\2.)C_6H_6(l)(5.5^oC)\rightleftharpoons C_6H_6(l)(60.6^oC)[/tex]
- For process 1:
To calculate the amount of heat required to melt the benzene at its melting point, we use the equation:
[tex]q_1=m\times \Delta H_{fusion}[/tex]
where,
[tex]q_1[/tex] = amount of heat absorbed = ?
m = mass of benzene = 91.5 g
[tex]\Delta H_{fusion}[/tex] = enthalpy change for fusion = 127.40 J/g
Putting all the values in above equation, we get:
[tex]q_1=91.5g\times 127.40J/g=11657.1J[/tex]
- For process 2:
To calculate the amount of heat absorbed at different temperature, we use the equation:
[tex]q_2=m\times C_{p}\times (T_{2}-T_{1})[/tex]
where,
[tex]C_{p}[/tex] = specific heat capacity of benzene = 1.73 J/g°C
m = mass of benzene = 91.5 g
[tex]T_2[/tex] = final temperature = 60.6°C
[tex]T_1[/tex] = initial temperature = 5.5°C
Putting values in above equation, we get:
[tex]q_2=91.5\times 1.73J/g^oC\times (60.6-(5.5))^oC\\\\q_2=8722.05J[/tex]
Total heat absorbed = [tex]q_1+q_2[/tex]
Total heat absorbed = [tex][11657.1+8722.05]J=20379.2=20.38kJ[/tex]
Hence, the amount of heat required for melting of benzene is 20.38 kJ
