pH Flashcards
What is the concentration of water?
55.5 M
What is Ka and its equation.
The acid dissociation constant. Ka = ([A-][H30+])/[HA]
What is Kw
The dissociation constant for water [OH-][H3O+]
Kw = 10^-14
pOH + pH = 14
What is Henderson-Hassalbach equation?
pH = pKa + log [A-]/[HA]
How would you calculate the isoelectric point of alanine?
Below pH = 2, there is form 1 which has a positive charge. After it loses a hydrogen, it is uncharged and that is its isoelectric form (form II). Then as you go past pH = 9, you get a negative charge. So you take the pka’s on either side of the isoelectric point and average them. Even if there are multiple isoelectric points, you just take the two on either side.
What is an equivalent and what is normality.
How many equivalents in H2SO4
How many moles are present in 250 mL of a 2 N of H2SO4.
Equivalent is defined as the amount of the molecule that can donate or accept 1 mole of protons.
1 equivalent of H2SO4 would be 1/2 because one mole of H2SO4 would donate 2 moles of protons.
Normality would be the number of equivalents in one liter of solution. SO the answer is .25 mole
An infection caused the lumen of his intestines to go from 6.5-5.5. Decrease in ph is likely to have what effect?
Denature proteins that reach intestine with native structure intact
Disrupt hydrogen bonding of tertiary structur
Inhibit intestinal enzymes that rely on histidine
It will have little effect on hydrolases
pH needs to fall very low to disrupt hydrogen bonds and denature proteins.
All intestinal hydrolases ( proteases, glycosidases) use acid base catalysis so changes in pH will have an effect.
As is same with histidine which operates over a narrow range
