2.2 Water Flashcards
Why is water polar
In a water molecule there is two hydrogen and an oxygen but because oxygen has a larger mass (more protons) electrons sit closer to it. This makes the oxygen molecule slightly negative and hydrogen molecules slightly positive.
What are condensation and hydrolysis reactions
-Condensation reactions are when two molecules join together with the removal of water they usually join via two OH groups
-Hydrolysis reactions are when two molecules split with the addition of water
Why does water have a high specific heat capacity
-Specific heat capacity is a measure of kinetic energy of molecules
-Water has hydrogen bonds holding molecules together tightly so therefore lots of energy is required to raise the temperature and kinetic energy
Why is it important that water has a high specific heat capacity
-So that living things(prokaryotes and eukaryotes) have a stable temperature for enzyme controlled reactions
-Aquatic organisms environment doesn’t fluctuate in temperature a lot making it easier for them to survive.
Why does water have a high latent heat of vaporisation and why is this important
-Hydrogen bonds mean lot of energy is required to break bonds and water to become gaseous
-Therefore it can be used as a coolant as lots of energy is released when it evaporates e.g sweat
Why is water cohesive and adhesive
-Water is polar so therefore are attracted to eachother(Cohesion) and is therefore attracted to other polar molecules(adhesion)
Why is it important that water is cohesive and adhesive
-Helps keep blood together and water in transpiration is pulled up due to cohesion.
-This also causes surface tension which creates a layer of water able to resist a force because the water molecules are being pulled inwards due to cohesion.
Why does water have a lower density when solid
and why is this important
-When water becomes solid it forms four covalent bonds and creates a lattice shape which is less dense than liquid water
-Therefore when it’s cold ice will form an insulative layer on the top of a lake for e.g and prevent heat loss creating a stable environment for aquatic organism
