Question

If I don't want to use latent heat, can I convert ice into water by decreasing the pressure?

Answer 1

1. Water has freezing point at 0 degrees and at a pressure of 1 atm.

2. When the pressure is reduced (even highly) below 1 atm and the temperature is below 0 degrees that is ice, we observe that solid water does not change its state.

3. But, if the temperature is increased under these conditions upto 4-5 degrees of temperature, solid directly change to gaseous state, that is ice to vapour. This could be easily understood in your higher studies when you are able to understand phase diagrams of the systems.