To measure the specific heat in the liquid phase of a newly developed cryoprotectant, you place a sample of the new cryoprotectant in contact with a cold plate until the solution’s temperature drops from room temperature to its freezing point. Then you measure the heat transferred to the cold plate. If the system isn’t sufficiently isolated from its room-temperature surroundings, what will be the effect on the measurement of the specific heat?

(a) The measured specific heat will be greater than the actual specific heat;

(b) The measured specific heat will be less than the actual specific heat;

(c) There will be no effect because the thermal conductivity of the cryoprotectant is so low;

(d) There will be no effect on the specific heat, but the temperature of the freezing point will change.

In cryopreservation, biological materials are cooled to a very low temperature to slow down chemical reactions that might damage the cells or tissues. It is important to prevent the materials from forming ice crystals during freezing. One method for preventing ice formation is to place the material in a protective solution called a cryoprotectant. Stated values of the thermal properties of one cryoprotectant are listed here:

Melting point .......................................................... -20‑C

Latent heat of fusion .............................................. 2.80 × 10⁵ J/kg

Specific heat (liquid) ............................................... 4.5 × 10³ J/kg ∙ K

Specific heat (solid) ................................................. 2.0 × 10³ J/kg ∙ K

Thermal conductivity (liquid) .................................... 1.2 W/m ∙ K

Thermal conductivity (solid) ..................................... 2.5 W/m ∙ K