Acid Base Flashcards
H2O properties
highest density at 4 celsius so ice can float
boiling point 0 degrees
melting point 100 degrees
each H2O molecule forms 4 hydrogen bonds
solvent, dissolve solute
H2O dissociation
H2O –> H+ + OH-
pH formulas
pH=-log[H+]
log[H+] + log[OH-] = -14
pH + pOH = 14
neutral when pH=pOH (7)
dissociation constant Kd= [H+][OH-]/[H2O] = 1.8 x 10^-16 M
equilibrium constant Kw= [H+][OH-] = 1 x 10^-14 M^2
cell pH
~6.8-7.8
ionization
strong acids fully ionize in water, weak acids dont
strong acid
HCl–> H+ + Cl- (fully ionize), acids gives up H+
@0.01M [HCl]
pH=-log[0.01]
pH=2
strong base
NaOH –> Na+ + OH-
give up OH-
@0.001M [NaOH]
pOH=-log[0.001]
=3
pH= 14 - 3
=11
weak acids and bases
partially ionize in H2O
CH3COOH (acid) –> CH3COO- (conj base/salt) + H+
-weak acid with its conjugate base acts as a buffer
-when HA=A- then pH=pKa (at + or - 1 pH units)
henderson hasselbalch
weak acid:
pH= pKa + log [conj base/ HA] / [acid/ A-]
or [deprotonated]/[protonated]
weak base: BH2 (weak base) + H+ –> BH3+ (conj acid)
pH<pKa = in conj acid (protonated) form
pH>pKa= in conj base (deprotonated) form
buffer systems
intracellular and extracellular
intracellular: protein and phosphate
extracellular: bicarbonate HCO3
–> also in equilibrium with dissolved CO2 bc of carbonic anhydrase
RBC= Hb, hemoglobin buffer
–> diagrams for phosphate and bicarbonate buffers
bicarbonate, carbonic anhydrase, CO2 and ventilation
lungs can modify Co2 removal by increasing ventilation
kidneys can modify HCO3 excretion rate
-when CO2 made from fuel oxidation is made into H2CO3 by carbonic anhydrase in the RBC. H2CO3 ionized and exported into plasma via HCO3-/Cl- transporter
-when reach lungs CO2 released - carbonic anhydrase helps get rid of CO2
-hyperventilization increased blood pH bc release more CO2 out of body, less H+ ions
maintain body pH
-body produces 13-22 mol/day of acid
maintain neutral pH by
-excrete CO2 in lungs
-NH4 (ammonia) in urine
