Acid-Base Flashcards
comparison of ice and water
ice: ___ hydrogen bonds per water molecule
water: ___ hydrogen bonds per water molecule
ice: hydrogen lifetime is about _____
water: hydrogen lifetime -a bout _____
4
2.3
10 microsecs
10 psecs
Ionization of Water
1) O-H bonds are ____ and can dissociate heterolyrtically
2) products are a ______ and a ____
3) dissociation of water is a rapid ______ process
4) most water molecules remain ______, thus pure water has very low ________
5) the equilibrium is strongly to the ____
6) extent of dissociation depends on the ________
polar proton (H+) and a hydroxide ion (OH-) reversible un-ionized, electrical conductivity left temperature
in pure water, the chemical concentration of H+ and OH- are ____. because of the very small degree of _____ we can write the chemical concentration of water as _____, which is its non-dissociated concentration at 25 degrees C
equal
dissociation
55.5 M
the negative logarithm of the hydrogen ion concentration
pH
when the [H+] is > than [OH-] the solution is said to be _______
when [OH-] and [H+] are equal, the solution is said to be ______
when [H+] is
acidic
neutral
basic
the pH of our plasma is _____
the pH of our gastric juices is ____
7.4
1-2
_____ is a digestive enzyme secreted into gastric juice, which has a pH of ____, allowing it to act optimally
pepsin, 1.5
_____ a digestive enzyme that acts in the small intestine, has a pH optimum that matches the neutral pH in the lumen of the small intestine
trypsin
______ of bone tissue is a hydrolytic enzyme thought to aid in bone mineralization
alkaline phosphatase
a substance that contains hydrogen and dissociates in water to contain ____
acid
H+
substance that contains a hydroxyl group dissociates in water to yield ____
base
OH-
any species that donates an H+
bronsted lowry definition of acid
any species that accepts an H+ ion
bronsted lowry definition of a base
oxoacids where the number of oxygens ___ the number of hydrogens by ____,
ex: ____, _____
strong acid
exceeds
2 or more
HNO3, H2SO4
hadrohalic acids
strong acid
HCl, HBr, HI
(carbon-based) include at least one COOH group
weak acid
organic acids
oxoacids where the number of oxygens _____ or ______ the number of hydrogens
ex)
weak acid
equals, exceeds
HNO2, H3PO4
Ka is _____ over ______, the stronger acids will have at equilibrium, a _______ of the dissociation products compared to the undissociated acid
products, reactants
higher proportion
higher Ka means ______
stronger acid
larger the pKa, the _____ the acid
weaker
describes the dissociation of a weak acid in the presence of its conjugate base
Henderson-Hasselbalch equation
analytical method used to determine the amount of acid in a solution
titration
at incremental points along the titration process, the pH of the solution is determined and plotted against the OH- amount added
this is called the ______
titration curve
the dissociation of the weak acid is ________ to the molar equivalents of strong base added
proportional
titration curves of weak acids
they all have the same shape
the point of half titration is the point where pH equals pKa
curves of different weak acids will be paralell along the Y-axis
mixtures of weak acids and their anions
buffers
buffers ______ in pH
resist change
buffering capacity of acid/anion system is _______ at ph=pKa
greatest
buffering capacity is ___ when the pH differs from pKa by more than 1 pH unit
lost
buffer systems in vivo are mainly based on:
phosphate, bicarbonate, histidine
buffer systems in vitro are often based on:
sulfuric acids of cyclic amines
