Different-sized solutes penetrate pores in the stationary phase to different extents. The largest solutes are eluded first

Molecular (size) exclusion chromatography

Molecular exclusion chromatography separates by size, so the large molecules______, and the solid stationary phase has a_____gel

elude first, porous

What is the mobile phase?

-the solvent moving through the column

- a liquid or gas

What is the stationary phase?

-the one that stays in place inside the column

- a viscous liquid chemically bonded to the inside of a capillary tube or packed column

In Ion exchange chromatography, what eludes first in an anion exchange chromatography?

The positively charged molecules will elude first because the stationary phase attracts the negatively charged molecules.

In Ion exchange chromatography, what eludes first in an cation exchange chromatography?

The negatively charged molecules will elude first because the stationary phase attracts positively charged molecules.

Retention time, t_r is the

elapsed time between injection and arrival

Retention volume, V_r, is the volume of

mobile phase required to elute a particular solute from the column

Gaussian chromatography states that if the peaks are farther apart,

the better the separation

Gaussian chromatography states that the longer the peak resides in a column,

the broader the band width

A resolution____ than 1.5 is highly desireable

greater

The narrower the peaks are, the____the separation, and the ___the resolution

better, higher

How does the column length affect the resolution?

increasing the column length allows for more separation time, and increases retention time and run time

How does temperature affect resolution?

raising the temperature in GC decreases the retention time by reducing the partition coefficient, allowing for faster elution. Higher temps can also reduce resolution and cause peaks to overlap

how does coating thickness affect resolution?

A thicker stationary phase will increase the retention time by providing more interaction time for analytes, enhancing the separation. Too thick can lead to excessive broadening and reduced efficiency

Which column has a larger plate number?

A(blue)

Which column has a larger plate height?

B (blue)

1. Which column gives higher resolution?

2. Which column gives a greater separation factor?

3. Which compound has a higher retention factor?

1. A (blue)

2. A (blue)

3. B (green)

1. Which compound has a greater distribution constant?

B (green)

In Normal Phase HPLC, the polar column allows for polar analytes to have

longer retention times, so non-polar molecules eludes first

In Reverse Phase HPLC, the non-polar column allows for non-polar analytes to have

longer retention times, so polar molecules elude first

What does each letter stand for? H=A+(B/ux)+Cu_x

____ plate height

____Eddy diffusion (multiple path)

____longitudinal diffusion

____ linear flow rate of mobile phase

_____resistance mass transfer in stationary and mobile phases

H , A, B, u_x, C

A study of interaction between matter and radiation

Spectroscopy

Technique that uses light to measure chemical concentrations

spectrophotometry

What does each symbol stand for?

lambda: wavelength (nm)

V: frequency (sm^-1)

c: speed of light (3.0x10⁸m/s)

Electronic transition occurs when

molecules absorb UV or visible light, causing electrons to move to higher electronic energy levels

Vibrational transition occurs in the

infrared region, causing them to vibrate

Rotational transition occurs in the microwave region causing

molecules to rotate

Label the following picture of measuring absorbance:

1. light sources

2. wavelength selector (monochromator)

3. sample

4. Light detector

Absorption spectrophotometer measures

how much light is absorbed by a sample at specific wavelengths

Emission spectrometer measures

how much light emitted by a sample after it has been excited

Label the following for measuring emission:

1. light source

2. excitation monochromator

3. sample cell

4. emission monochromator

5. detector

Beers law: A=ε⋅b⋅C, what do each letters signify?

A= absorbance

b= path length of the sample cuvette

c=concentration of solution

You can find concentration by relating these 2 equations: A=ε⋅b⋅C and Y=mx+b. What symbols work hand in hand?

y= A

m=ε

x=b

b=C

Label Jablonski Diagram:

1. absorption (10¹⁵s)

2. Internal conversion

3. intersystem crossing to T

4. INtersystem crossing to S_o

5. Fluorescence (10^-8-10^-4 s)

6. Phosphorescence (10^-4-10² s)

Has shorter emission time, brighter emission, emission of photon during internal converion, and only glows when UV light hits it

Fluorescence

longer emission time, dimmer emission, emission of photon during intersystem crossing, and can be charged with UV light

Phosphorescence

Internal conversion is a nonradioactive transition between states with the

same spin

Intersystem crossing is a nonradioactive transition between states with

different spins

The process by which an atom or molecule loses electrons

Na → Na+ + e−

Oxidation

The process by which an atom or molecule gains electrons.

Cl2 + 2e− → 2Cl−

Reduction

This is the substance that gains electrons ( gets reduced)
while it causes another substance to be oxidized.

oxidizing agent

This is the substance that loses electrons ( gets oxidized)
while it causes another substance to be reduced.

reducing agent

Galvanic cells are spontaneous and

external energy is not required

In a reaction equation, the left is the____ and the right is the____

anode, cathode

The anode gets______ and the cathode gets ____

oxidized, reduced

If E>0, it is a _____reaction, and if E<0, it is a _____reaction

spontaneous, non-spontaneous