Question

water__at o degree centigrade​

Answer 1

Explanation:

It could be either solid, liquid or gas.

At standard pressure conditions, it depends on how you approach 0 degrees Celsius. Lets take some water at room temperature. As you start cooling it, its temperature keeps dropping, till eventually it reaches 0. As soon as you reach 0, if you stop, it will be in liquid state. Now if you keep removing heat, the temperature remains 0, while the liquid starts turning to solid by rejecting its latent heat fusion. As the last of the liquid part turns to ice, you have a solid at 0 degrees Celsius. Similarly, if you reverse the process and you heat ices and it reaches 0, it is solid at 0 degrees, and continue heating till you reach completely liquid at 0 degrees Celsius.

All the above described was at standard pressure value taken at sea level (101325 N/m 2 or 1.01325 bar). However, if you lower the temperature of water to 0 degrees maintaining it as a liquid, and then lower the pressure below the vapour pressure, the liquid water turns to vapour and now exists is gaseous state. For water at 0 degrees Celsius, the vapour pressure is about 613.283 N/m 2 or 0.613283 bar. So if you lower the pressure below this value, the liquid water at 0 degrees will turn to vapuor state.

So water at 0 degrees C can exist as solid, liquid or gas, depending on the conditions