Question

Pre lab 9

If the specific heat of methanol is 2.51 J/K-g, how many joules are necessary to raise the temperature of 86 g of methanol from 27 oC to 64 oC ?

(------------) J

Answer 1

Mass of methanol = 86 g.

Specific heat of methanol = 2.51 J/K.g

Initial temperature of methanol = 27ºC = (27 + 273) K = 300 K.

Final temperature of methanol = 64ºC = (64 + 273) K = 337 K.

Energy required to raise the temperature of methanol from 300 K to 337 K =

(mass of methanol)*(specific heat of methanol)*(change in temperature)

= (86 g)*(2.51 J/K.g)*(337 K – 300 K)

= (86 g)*(2.51 J/K.g)*(37 K)

= 7986.82 J

= (7986.82 J)*(1 kJ)/(1000 J)

= 7.98682 kJ

≈ 8.0 kJ (ans, correct to 2 sig. figs).