If I have a very big waterproof safe and I filled it with water and locked it, then froze it to say minus 200 would the water freeze ?

Do you need air to freeze water to ice?

 

It would freeze, but it might burst the safe.

Water expands when it turns to ice.
You don't need air for water to freeze- comes are often described as "dirty snowballs".

 

Thanks John,

For very big safe, substitute if for incerdibly thick streel box which would not expand or burst. The point of my question is, if water atoms are confined so they CANNOT expand surely they would not freeze, just slow down even at minus 200...what do you think?

If confined it would still become a solid at much lower temperature and higher pressure. If confined to a density no greater than 1.0 it would be a different crystal structure than regular ice.

http://www1.lsbu.ac.uk/water/ice_phases.html

With 18 possible crystal structures it may be a mixture of several types.

I could be mistaken here, but natural water without any additive being added I was always lead to believe that when the temperature dropped below freezing that water would freeze, and when the temperature rises water expands and becomes liquid. In a car cooling system without antifreeze mixture added back in the early days the engines cooling systems used to freeze and no damage was caused during that period, but when the cooling system water temperature did rise again the increase in pressure in the cooling system engine block would force the core plugs out, and sometimes crack the block. I never experienced a cracked block with a frozen engine before thawing out  

I understand also that it is possible to get freeze burns from cold liquids and gasses like R134a, but whether the liquid/gas while the temperature is dropping below freezing is actually expanding outwards I don't know, and if that were the case, would that not cause physical damage to the components? 

3 minutes ago, Casio said:

and when the temperature rises water expands and becomes liquid.

Check the density of liquid water compared to ice. Therefore ice floats on the surface of the water, not sinks. 

So because Ice is less dense than water, when it thaws it expands. Have I got that correct?

No. Water counterintuitively expands when it freezes due to the crystalline structure which forms so it contracts while thawing. 

Its maximum density is at about 4 C

2 hours ago, swansont said:

Its maximum density is at about 4 C

One of a number of water's properties that have profound effects for life, at least as we know it.