Week 1 Flashcards
True or false:
Organic compounds that form hydrogen bonds with water are not soluble in water
False- if they can form hydrogen bonds they are usually soluble in water
What is the equation for the Ion Product of water?
Kw = [H+][OH-] = 1 x 10 to the -14
at pH of 7 the solution is ______ and both the [H+] and the [OH-] are ______.
Neutral
1x10 to the -7 (equal parts H+ and OH+)
If the concentration of H+ is 1x10-6 , what is the concentration of OH- ?
Kw/[H+} = [OH-]
1x10-14/ 1x10-6 = [OH-]
[OH-] = 1x10-8
What is pH defined as ?
The negative log of the concentration of hydrogen ions in a solution. This determines the acidity of the solution.
what is the equation for pH ?
pH = -log[H+]
Define an acid?
An acid is a proton donor, and chemical that can “lose or donate” a hydrogen ion (proton) in a solution
Define a base?
A proton acceptor, any chemical that can “gain or accept” a Hydrogen ion (proton)
Define the Conjugate base?
The ion or molecule remaining after the acid has lost a proton
Is also referred to as the salt of the acid (often “ate” ending as opposed to “ic”)
Define Strong acids?
- completely dissociate at any pH
2. when added to water, complete dissociation into the conjugate bas and protons
What 3 Strong acids does the body create?
Sulfuric acid
Hydrochloric acid
Nitric Acid
What is the chemical composure of Sulfuric acid?
H2SO4
What is the chemical composure of Hydrochloric acid?
HCl
What is the chemical composure of Nitric Acid?
HNO3
True or false:
Strong Acids can sometimes be used as buffers
False - strong acids cannot for buffers (they always dissociate )
Define Weak acids?
- Partial dissociation into conjugate base and protons
- Ratio of conjugate base (salt) to weak acid can be adjusted by adding H+ or OH- to the solution
- Only weak acids can buffer aqueous solutions
What is the dissociation equation of a weak acid?
HA = H+ + A-
HA is weak acid concentration
A- is conjugate base concentration
H+ is proton concentration
What is the equation for the dissociation constant Ka?
Ka = [H+][A-] / [HA}
What is the relationship between pKa and Ka in equation form?
pKa = -log(Ka)
When the pH is equal to the pKa , what does that mean for the dissociation of the weak acid HA ?
50% dissociation
What is the Henderson-Hasselbalch equation?
pH = pKa + log {[A-]/[HA]}
In relation to the Henderson Hasselbalch equation, when the [A-] is equal to the [HA], what does that infer?
pH = pKa
When you increase the [HA] (acid) in the solution, what does it do?
brings pH down (inverse relationship)
When you increase the [A-] (conjugate base or salt), what does it do to the solution?
brings the pH up (Direct relationship)