what facts of water are good to know for the MCAT?

[Oh_Gee]

Let's make a list and explanations of how and why water deviates from other liquids such as it's most densest at 4 C and the negative slope of its phase transition graph. Water confuses me

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[sillyjoe]

Let's make a list and explanations of how and why water deviates from other liquids such as it's most densest at 4 C and the negative slope of its phase transition graph. Water confuses me

-extreme hydrogen bonding leads to high BP
-densest as a liquid when 4 centigrade. Lots of implications of this. Warmer water will be deeper when a lake is frozen. Ice floats on water
-negative slope in phase transition allows an isothermal increase of pressure to go from vapor --> solid --> liquid

 

[Oh_Gee]

-extreme hydrogen bonding leads to high BP
-densest as a liquid when 4 centigrade. Lots of implications of this. Warmer water will be deeper when a lake is frozen. Ice floats on water
-negative slope in phase transition allows an isothermal increase of pressure to go from vapor --> solid --> liquid

can you please explain why warmer water will be deeper? and also is there a situation when ice will sink?

 

[sillyjoe]

can you please explain why warmer water will be deeper? and also is there a situation when ice will sink?

Ice won't sink because liquid water is more dense than solid water. The only situation where ice will sink is if the ice is made with heavy water, but this is just another way of saying that an object will only sink in water if it is more dense than water.

Let's say you are at a lake that is frozen on top. The warmest water will be the deepest water since water is densest at 4 degrees. Therefore, if there is ice on the top, water that is 0 degrees, 1 degrees, 2 degrees, and 3 degrees will be higher than the water at 4 degrees, i.e. the water at 4 degrees will be deepest when the external environment is freezing.

 

[Oh_Gee]

Ice won't sink because liquid water is more dense than solid water. The only situation where ice will sink is if the ice is made with heavy water, but this is just another way of saying that an object will only sink in water if it is more dense than water.

Let's say you are at a lake that is frozen on top. The warmest water will be the deepest water since water is densest at 4 degrees. Therefore, if there is ice on the top, water that is 0 degrees, 1 degrees, 2 degrees, and 3 degrees will be higher than the water at 4 degrees, i.e. the water at 4 degrees will be deepest when the external environment is freezing.

oh okay.
and why is water densest at 4 C? and how does density increase/decrease as you move from left (say -10 C) to right ( 110 C) of the water transition graph

 

[sillyjoe]

oh okay.
and why is water densest at 4 C? and how does density increase/decrease as you move from left (say -10 C) to right ( 110 C) of the water transition graph

I think that is because it has enough hydrogen bonding to keep it together closely without maximizing the hydrogen bonding to create the less dense crystal lattice structure.

All you need to know is water is at it's densest at 4 degrees. -10 centigrade water will be more dense than 110 centigrade water which is a gas.

 

[Oh_Gee]

thanks for all the info. one last ?
I believe the h-bonding of water would give it an increased surface tension compared to other liquids. random question: so would it be harder to blow bubbles into water or into a liquid with less surface tension. I remember reading somewhere that liquids with high surface tensions resist change but shrinking in.