Analytical Chemistry Final- ACS Exam,
Fundamentals of Spectrophotometry,
Atomic Spectroscopy, Mass
Spectroscopy 100% Correct
ppm
(grams analyte/grams sample)x10^6
femto-
10^-15
ppt
(grams analyte/grams sample)x10^3
gram analyte/liter solution
Accuracy vs. Precision
closeness of the mean to the "true value"
reproducibility of individual measurements
pH vs [H3O+] equations
-log[H3O+]
10^-pH
random error vs systematic error
random error: variation in a measurement that occurs unpredictably
systematic error: consistent, repeatable error
Reactants vs products side for K
Ka vs 1/Ka
,what is the k equation and what does it exclude
k=products/reactants
- this does not include any solids or liquids, only aqueous solutions
Kw 2 eq
[H30+][OH-]
Ka*Kb
pKw=
pH+pOH
A weak acid consists of a Ka value of
10^-3 or less
Direct Titration
standardized titrant is added to the analyte until the end point is observed
Back and Indirect Titration
Back titration:
-excess of a known reagent is added to unknown solution
-remaining excess reagent is titrated with another solution
Indirect:
includes a back titration, and occurs whenever a direct titration is not feasible
Push the reaction to the products side if you have a
Push the reaction to the reactants side if you have a
very large K value
very small K value
You need to consider the autoprotolysis of water when
the concentration is <10^-5
Henderson-Hasselbalch equation
pH=pKa+log[A-]/[HA]
, zwitterionic form
an ion that can be an acid or a base
Acid-Base Titration at the equivalence point
solve for x and then take the -log([H3O+])
How do you tell which endpoint is better in a polyprotic acid-base titration curve?
The endpoint that has the largest change in pH
What are indicators considered?
a weak acid with special characteristics
monodentate
one lone pair on the reactant
how is EDTA written in a stoichiometric reaction?
Y^4-
Use of EDTA titrations
Determining the concentration of metal ions in a solution
What pH is it best to work at with an EDTA Titration?
basic to keep the Kf' large
Why do you add auxilliary complexing agents to EDTA titrations?
To stop the metal from precipitating with OH- since the metal will bind with the
complexing agent.
Auxilliary Complexing Titration at 0 mL
use the alpha m equation for finding concentration and then take the -log[metal]
How do you solve a back titration?
1. Find the mols of EDTA used total
2. Find the mols of EDTA in excess
Fundamentals of Spectrophotometry,
Atomic Spectroscopy, Mass
Spectroscopy 100% Correct
ppm
(grams analyte/grams sample)x10^6
femto-
10^-15
ppt
(grams analyte/grams sample)x10^3
gram analyte/liter solution
Accuracy vs. Precision
closeness of the mean to the "true value"
reproducibility of individual measurements
pH vs [H3O+] equations
-log[H3O+]
10^-pH
random error vs systematic error
random error: variation in a measurement that occurs unpredictably
systematic error: consistent, repeatable error
Reactants vs products side for K
Ka vs 1/Ka
,what is the k equation and what does it exclude
k=products/reactants
- this does not include any solids or liquids, only aqueous solutions
Kw 2 eq
[H30+][OH-]
Ka*Kb
pKw=
pH+pOH
A weak acid consists of a Ka value of
10^-3 or less
Direct Titration
standardized titrant is added to the analyte until the end point is observed
Back and Indirect Titration
Back titration:
-excess of a known reagent is added to unknown solution
-remaining excess reagent is titrated with another solution
Indirect:
includes a back titration, and occurs whenever a direct titration is not feasible
Push the reaction to the products side if you have a
Push the reaction to the reactants side if you have a
very large K value
very small K value
You need to consider the autoprotolysis of water when
the concentration is <10^-5
Henderson-Hasselbalch equation
pH=pKa+log[A-]/[HA]
, zwitterionic form
an ion that can be an acid or a base
Acid-Base Titration at the equivalence point
solve for x and then take the -log([H3O+])
How do you tell which endpoint is better in a polyprotic acid-base titration curve?
The endpoint that has the largest change in pH
What are indicators considered?
a weak acid with special characteristics
monodentate
one lone pair on the reactant
how is EDTA written in a stoichiometric reaction?
Y^4-
Use of EDTA titrations
Determining the concentration of metal ions in a solution
What pH is it best to work at with an EDTA Titration?
basic to keep the Kf' large
Why do you add auxilliary complexing agents to EDTA titrations?
To stop the metal from precipitating with OH- since the metal will bind with the
complexing agent.
Auxilliary Complexing Titration at 0 mL
use the alpha m equation for finding concentration and then take the -log[metal]
How do you solve a back titration?
1. Find the mols of EDTA used total
2. Find the mols of EDTA in excess
