Question

state the effect of heat in the following examples.(a)cooking of vegetables(b)sterilization of surgical instruments(C)freezing of water

Answer 1

Dear student,

a) We cook food at high temperatures in order to kill harmful pathogens it may contain. Cooked food is easy to digest. Cooking also improve food's appearance, texture and flavour. But boiling reduces the nutritive value of the food to some extend.
b) Sterilization of surgical instruments include autoclaving (steam under pressure), dry heat sterilisation and chemical sterilisation.The heat applied during sterilisation would disinfect the instruments. Micro organisms can not withstand high temperature.
c) Due to Mpemba effect, hot water freezes faster than cold water. When two bodies of water with different temperatures are exposed to low temperature (less than zero), hotter water freezes first. Because water evaporation will be high in hot water leaving less water to freeze.

Regards.