Water And Its Functions Flashcards
(38 cards)
What is water made of?
Two hydrogen atoms and one oxygen atom.
What charge does a water molecule have?
No overall charge.
What charge does the oxygen atom have?
A slight negative charge.
What charge to the hydrogen atoms have?
A slight positive charge.
What is a water molecule described as and why?
Dipolar, as it contains both positive and negative poles.
What do different poles do?
Attract.
What is the positive pole in a water molecule attracted to?
The negative pole of another water molecule.
What are the attractive forces between the charged poles?
Hydrogen bonds.
What feature do hydrogen bonds have?
They are weak.
What do hydrogen bonds together form?
Important forces that cause water molecules to stick together, giving water it’s unusual properties.
What does it mean for water molecules sticking together?
It takes more energy (heat) to separate them than if they did not bond to one another.
What does it mean if water takes lots of energy to separate?
It has a high boiling point.
What would water be without hydrogen bonding?
A gas (water vapour).
Why does water have a high specific heat capacity?
As it takes more energy to heat a given mass of water.
What does water do as it has a high specific heat capacity?
It acts as a buffer against sudden temperature variations.
What’s a benefit of water acting as a buffer against temperature variations?
It makes the aquatic environment a temperature-stable one as well as it buffers organisms against sudden temp changes.
What does hydrogen bonding between water molecules also mean?
That is requires a lot of energy to evaporate 1 gram of water.
What is the energy needed to evaporate one gram of water called?
Latent heat of vaporisation.
What is an effective means of cooling and how?
Evaporation of water such as sweat, as body heat is used to evaporate the water.
What is cohesion?
The tendency of molecules to stick together.
What does water have related with its hydrogen bonding?
Large cohesive forces.
What does waters large cohesive forces allow?
It to be pulled up through a tube such as a xylem vessel in plants.
What happens when water molecules meet air?
They tend to be pulled back into the body of water rather than escaping from it.
What is surface tension?
Where the waters surface acts like a skin.
