3.2 Water Flashcards
How do the hydrogen bonds in water form
Polar molecules interact with each other as the positive and negative regions of the molecule attract each other and form bonds called hydrogen bonds
What are the characteristics of hydrogen bonds in water
They form in high numbers
Weak interactions which constantly break and reform
Gives water it’s unique characteristics which help to sustain life
What are the characteristics of waters boiling point
Unusually high boiling point
Smaller than CO2 and O2 molecules and are lighter
Liquid at room temp and takes lots of energy to increase the temp and make it gaseous
Becomes less dense in solid state
Why does water become less dense as a solid
Below 4 degrees the hydrogen bonds fix the positions of the polar molecules slightly further apart than the average distance in liquid state producing a less dense solid than liquid water
What are the cohesive properties of water
It moves as one mass because the molecules are attracted together
What are the adhesive properties of water
Water molecules are attracted to other molecules eg. When you wash your hand the water doesn’t all run straight off
What is the reason for water having surface tension
Water molecules are more cohesive to each other than they are to the air resulting in surface tension
Why is water being polar vital for life
This allows water to act as a solvent in which many solutes in an organism can be dissolved. It also acts as a medium for chemical reactions and helps transport dissolved substances in and out of the cell
How does water act as an effective transport medium
Cohesion and adhesion result in capillary action which is how water can rise up a narrow tube against the force of gravity
How and where does water act as a coolant
It helps to buffer temperature changes during chemical reactions in prokaryotic and eukaryotic cells due to large energy needed to overcome hydrogen bonding.
Why is it important to maintain constant temperatures in cells
As enzymes are only active in a narrow temperature range
Why is water a good environment for organisms such as fish
It is stable as it does not change temperature or state easily
