Question

Ethyl chloride (C2H5Cl) boils at 12∘C. When liquid C2H5Cl under pressure is sprayed on a room-temperature (25∘C) surface in air, the surface is cooled considerably. Assume that the heat lost by the surface is gained by ethyl chloride. What enthalpies must you consider if you were to calculate the final temperature of the surface?

Check all that apply.

a) The specific heat of C2H5Cl(g)

b) The specific heat of the solid surface

c) The specific heat of C2H5Cl(l)

d) The enthalpy of vaporization of C2H5Cl(l)

Answer 1

answers : ALL 4 choices are correct

a) The specific heat of C2H5Cl(g)

b) The specific heat of the solid surface

c) The specific heat of C2H5Cl(l)

d) The enthalpy of vaporization of C2H5Cl(l)

the reason is that .

conversions :

25 -----------------> 12 -----------------------> final temperature

25 ------------------> 12 ( gas specific heat )

12 -----------------------> (enthalphy of vaporization)

12---------------------> final temperature (The specific heat of liquid)

solid phase may be appered in between 12 to final so specific heat also needed