Question

Heat the oxygen to about 150 K. What state of matter is this?

Answer 1

Answer:

• Gas

Explanation:

It is easier if you convert the kelvin temperature into Celsius degrees:

• ºC = T - 273.15 = 150 - 273.15 = -123.15ºC

Now, you know that that is a very cold temperature. Thus, may be the oxygen is not gas any more but it changed to liquid . . . or solid?

You must search for the boiling point and melting (freezing) point of oxygen in tables or the internet. At standard pressure (about 1 atm) they are:

• Melting point: −218.79 °C,

• Boiling point: −182.962 °C

That means that:

• below -218.79ºC oxygen is solid (not our case).
• between -218.79ºC and -182.962ºC oxygen is liquid (not our case)
• over -182.962ºC oxygen is a gas. This is our case, because -123.15ºC is a higher temperature than -182.962ºC.

Hence, the state of matter of oxygen at 150K, and standard pressure, is gas.