Question

Give your recommendation about the concept of specific heat capacity and latent heat can
be utilized in ice- cream industry to cool the ice creams and in cooking food in the kitchen. In the
latent heat formula, Q = ± mL, how can you make the significance of dual sign in the formula?
How can you provide scientific justifications to prove that there are some differences in total
cooking time in open vessels compared that with a closed vessel like pressure cooker

Answer 1

The positive and negative sign indicates that in some processes heat will be added to the system and in some processes heat will be removed from the system. L is the latent heat which is the amount of heat which has to be removed or added for any phase change. If ice has to be formed from liquid then heat has to be removed at constant temperature. And if liquid has to be formed from solid then we have to add some latent heat again at some constant temperature.

the difference in total cooking time is due to that reason, as the boiling point or melting point of any substance depends upon the atmospheric pressure hence the latent heat that has to be removed or provided also depends upon the atmospheric pressure. At lower atmospheric pressure, the latent heat will be greater which will take more time to be removed or provided. For example at hilly areas which are at greater altitudes have lesser atmospheric pressure it will take more time for cooking rather than at plane areas.