Chapter 2.2- Water Flashcards
What is the molecular formula of water?
H2O
What is each O-H covalent bond?
polar
What are the five properties of water?
-Water is sticky (adhesion and cohesion)
-Water moderates temperature
-Solid Water is less than dense than liquid water
-Water is a solvent
-Water can dissociate
What is surface tension?
Adhesion
Why is water adhesive and cohesive?
-Since it’s polar, it allows it to form hydrogen bonds with each other (cohesion) and with other atoms (adhesion)
How does water moderate temperature?
-Water has a high specific heat
-High heat of vaporization
How is solid more dense than liquid water?
-Solid (hydrogen bonds are stable)
-Liquid (hydrogen bonds constantly break and re-form)
How is water a solvent?
-It’s a “Universal” Solvent
-excellent solvent for polar and charged molecules and compounds
What is hydrophilic?
Water loving
Are molecules hydrophilic?
most biological molecules are hydrophilic
How do hydrophilic molecules work?
H2O forms a “hydration shell” around hydrophilic substance
In pure water, what are the numbers of H+ and OH-?
They are equal to each other
What does water dissociate to?
In pure water, small amounts can dissociate into hydrogen ions (H+) and hydroxide ion (OH-)
what pH?
the amount of H+ in solution, which measure the solutions acidity
How do the concentrations of H+ change?
They change by a factor of 10 for each unit of the scale
what is the Ph of something acid?
pH <7.0
What are acids made of?
compounds that release or donate H+ ions
What does adding acid to water do to pH?
it lowers it
what is the pH of a base?
pH>7.0
compounds that release OH- or combine it with H+
Bases
What does adding base to water do to pH?
it increases pH
What are buffers?
compounds that resist changes in pH
How do buffers resist change in pH?
it absorbs excess H+ or OH-
What type of buffer system does blood contain?
Carbonic acid-bicarbonate buffer system
What is pH of blood?
7.4
(range 7.35-7.45)
