2.2 Water Flashcards
What is water made up of?
Two hydrogen atoms covalently bonded to an oxygen atom (H2O)
Why is water polar?
It has a slight charge difference across the different poles of the molecule
What dioes the weak associations across the wtaer molecules allow?
Weak associations with other polar molecules
What is the bond between water and hydrogen?
Hydrogen (stronger bond than other polar associatins due to its high eletronegativity)
Why is water a good medium for living organisms?
Due to its ability to absorb significant amounts of heat before changing state
What makes water able to absorb significant amounts of heat before changing state?
Extensive hydrogen bonds between water molecules -> the H bonds need to be broken before a change in state occurs
What are the similarities between methan and hydrogen?
They both have tetrahedral orbital formations
What are the diffrerences between water and methane? (2)
The thermal properties
Water is polar / methane is non-polar
Heat absorption before changing state
What polar properties differ between water and methane?
Water is polar so can form intermolecular hydrogen bonds (high electronegativity or oxygen atom)
Methane is non-polar can form weak disperision forces between molecules
What water absorption properties cause water and methan to differ? (3)
Water has a higher melting point
Water has a higher specific heat capacity
Water has higher heat of fusion
Why is water better for sweat?
Becuas eit has a higher specific heat capacity, when the sweat evaporated the skin is cooled
What are cohesive properties?
Cohesion is the ability of like molecules to stick together (between water molecules will form hydrogen bonds)
What are adhesion properties?
The ability of dissimilar molecles to stick together (water will fomr intermoelcular associations with polar chanrged molecules?
What kind of substances can water dissolve?
Any substance that contains charged particles (ion) or electronegative electrons (polarity)
What are hydrophilic substances?
Substances that freelky associate and readily dissolve in water
(All polar molecules and ions)
