During an experiment, ice and water were placed in a perfectly insulated thermos flask at 0 °C. Describe this system when it phase reaches equilibrium.

At equilibrium state, the water will have turned into ice.

Explanation:

An Equilibrium phase is defined as a stage when chemical potential of any component ( solid liquid or gas) present in the system remains steady with time. So, in this situation, because the system is perfectly insulated, no heat will be gained or lost. The water and ice are both at exactly 0 °C, then that temperature will remain constant. As time goes on, the water will freeze and the system will become all ice.

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.