ELECTROCHEMISTRY Part 1 Flashcards
- measurement of differences in voltage at a constant current
- unknown voltage introduced into this circuit opposes a known ____
- ______ is measured by comparison to determine the voltage required to exactly oppose the flow of current in the test circuit
- relationship between the measured voltage and the sought-for conc is shown by the ______ - measurement of differences in current at a constant voltage
- used to measure ___,____,____, & ____ conc
- relationship between the differences in current and voltage is shown by the ________
- POTENTIOMETRY
- REFERENCE VOLTAGE
- VOLTAGE OF UNKNOWN
- NERNST EQUATION - POLAROGRAPHY
- trace metals, oxygen, Vit. C, and amino acid
- ILKOVIC EQUATION
- measurement of the amount of electricity at a fixed potential
- ______ equal to a current flow of 1 ampere per second
- relationship is expressed by _____ - measurement of the amount of current that flows when a constant voltage is applied to measuring electrode
- measurement of the current flow between two non-polarizable electrodes between which a known electrical potential is established
- COULOMETRY
- COULUMB
- FARADAYS LAW - AMPEROMETRY
- CONDUCTOMETRY
SEPARATION OF SUBSTANCES
- separation is based on solubility
- precipitate is studied by (3) - separates dissolved materials; removes particulate matter
- separation of dissolved molecules
- movement through a semi-permeable membrane driven by a force
- movement through a semi-permeable membrane more freely
- PRECIPITATION
- turbidimetry, chemical rxn, gravimetric - ULTRAFILTRATION
- DIALYSIS
- ULTRAFILTRATION
- DIALYSIS
SEPARATION OF SUBSTANCES
_____: compounds are separated based on differences in affinity between mobile & stationary
2 phases
1. coated or uncoated
2. flowing gas or liquid (eluent or carrier)
general types
1. molecules separated are adsorbed at the surface of a solid support
or flow with the mobile phase
2. solid support is coated with a film of water or non-volatile organic
CHROMATOGRAPHY
2 phases
1. Stationary
2. Mobile
general types
1. Adsorption Chromatography
2. Partition Chromatography
Types of Chromatography
_____: partition is between water & organic solvent
1. solid phase:
2. mobile phase:
- if molecules are more soluble in flowing solvent = ____ in paper
- if molecules are more soluble in water = ____ in paper
3. RF: ratio of the distance of movement by a compound to the distance of the solvent front
- a = distance travelled by
- b = distance travelled by
PAPER CHROMATOGRAPHY
1. Paper composed by CELLULOSE
2. ORGANIC SOLVENT
- FASTER
- SLOWER
3.
- COMPOUND FROM ORIGIN TO FRONT
- SOLVENT
Types of Chromatography
_____: flat sheet of chromatographic material; for screening of drugs or abuse
1. solid phase:
2. mobile phase:
3. Qualitative analysis:
4. Quantitative analysis:
THIN LAYER
1. water bound to silica or alumina (aluminum oxide + aluminum hydroxide)
2. organic solvent
3. based on colors and positions
4. remove spots and extract
Types of Chromatography
_____: separation is based on electrical charge
1. solid phase (3)
2. mobile phase:
3. Anion exchangers
4. Cation exchangers
ION EXCHANGE
1. Aluminum silicate, Polysaccharides, Synthetic resins
2. Water
3. capture anions
4. capture cations
Types of Chromatography
_____: separation is based on differences in molecular size
- solid phase (3)
- mobile phase:
- aka
GEL FILTRATION
- Polyacrylamide, Sephadex, Porous beads
- Flowing water
- Molecular Sieve / Gel Permeation / Size Exclusion / Molecular Exclusion
Types of Chromatography
_____: confirmation & quantitation of drugs
1. solid phase
2. mobile phase:
3. based on partition
4. based on adsorption
Gas Chromatography
- diatomaceous earth (silica) coated with a non-volatile organic liquid
- inert carrier gas (Helium or Nitrogen)
- Gas – Liquid Chromatography
- Gas – Solid Chromatography
Types of Chromatography
_____: selective adsorption with application of pressure
1. for high ____ compounds
HPLC
1. MW Compounds
