ICSE Class 9 Answered

Dry ice does not melt like normal ice.The melting point of dry ice is not 0° C.

Dry ice is solid form of carbon dioxide(frozen carbon dioxide).At normal atmospheric conditions dry ice does not melt whereas it sublimes (changes its state directly from solid to gaseous state) without going to liquid phase.Dry ice sublimes at −78.5 °C at atmospheric pressures.

Dry ice melts only at very high pressure.The pressure of the vapor of dry ice at its 
melting point is about 5 atmospheres. This occurs at a temperature 
of -57° C.