# Ice should sink??

Discussion in 'Secondary Education' started by edu, Jan 10, 2014.

1. ### eduRookie

Joined:
May 23, 2009
Messages:
80
0

Jan 10, 2014

Please help. Ice is more denser than water when temperature of water ≥9°C. Then why ice doesn't sink in water at these temperatures? Today I dropped an ice cube in water at room temperature and ice was floating.Is this a contradiction?
Density chart: http://www2.volstate.edu/chem/1110/Density_of_Water.htm

Joined:
Feb 2, 2012
Messages:
874
0

Jan 10, 2014

4. ### eduRookie

Joined:
May 23, 2009
Messages:
80
0

Jan 10, 2014

Yes , ice is lighter only between 0 and 8.2 C. But at more than 8.2C ice is denser than water. I am specific about temperatures.

5. ### ajrRookie

Joined:
Feb 13, 2013
Messages:
62
0

Jan 10, 2014

What the heck are you talking about?

The density of Ice Ih (the normal variety of ice that forms at 1 atmosphere when solidification occurs between -100 and 0 degrees Celsius) is .917 g/cm^3.

At no point does the density of subcritical water drop below .999 g/cm^3.

Edit:

Turns out the density of water at 100 degrees is just under .960 g/cm^3, but I can't find a density diagram to tell you how much pressure the water would have to be under to get down to .917 g/cm^3.

Edit 2:

After a little more research, you'd have to bring the water up to just under 150 degrees C before ice would sink. This requires a pressure vessel under about 80 psi.

Joined:
Jan 26, 2012
Messages:
1,841
52

Jan 10, 2014

Seriously?

7. ### eduRookie

Joined:
May 23, 2009
Messages:
80
0

Jan 10, 2014

Yes, you are right. I was looking at 0C ice, not 0C liquid water. They both are two different phases. Sorry for confusion. Thank you for your patience and help.

8. ### czaczaMultitudinous

Joined:
Sep 30, 2001
Messages:
24,956
2,116

Jan 10, 2014

Are you teaching science?

Joined:
Nov 20, 2010
Messages:
290
0

Jan 11, 2014

Joined:
Jan 7, 2013
Messages:
74