water and pH 9/7 Flashcards
what is a dielectric constant?
physical property that reflects number of dipoles in a solvent
why does water have a high dielectric constant?
it is effective in screening electrostatic interactions between dissolved ions and thus electric forces are less strong in water
what is the difference between a C bonded to an H and an O/N?
C-H is nonpolar and not soluble in water while C-N/O is polar and soluble in water because hydrogen bonds can form
what happens when many water molecules are bonded to eachother?
proton jumping
how are entropy and hydrophobic groups related?
entropy decreases as water molecules form a cage around hydrophobic groups as nonpolar molecules group together
differences between condensation (dehydration) and hydrolysis
condensation: two biomolecules are linked and water is a product
hydrolysis: biomolecules is cleaved and water is a reactant
if a solution is mostly water it is a
dilute aqueous solution
pH doesn’t apply if
a solution is not dilute
pH is
negative log of hydronium ion concentration
what is Kw?
ionization constant for water = 10-14
how are strong acids/bases related to water?
they completly dissolve in water (if a strong acid is added to water the H+ is equal to acid concentration and if a strong base the OH- is equal to base concentration)
what type of acid/base are almost all biomolecules?
weak acid/base
what do you have to know to determine pH of a weak acid or base?
equilibrium constant of dissociation reaction
what does a weak acid dissociate into?
H+ and conjugate base
what is the henderson hasselbalch equation?
