Summary
Summary of Chapter 29 OCR A Chemistry
High quality, detailed notes summarising everything you need to know for OCR A Chemistry Chapter 29. All the content on specification included.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
l l l O l l 2 IChapter 29 -
Chromatography and
spectroscopy
29 I .
Chromatography and functional group
analysis
stationary phase -
does not move and is
normally a solid / liquid supporting a solid
does
mobile phase move and is
normally a liquid /gas
-
,
chromatography -
separation of a mixture by passing it in solution 1 suspension through a medium
in which the components move at different rates
polar -
a molecule with an overall
charge
non polar a molecule with no overall
-
charge
-
retardation factor the distance travelled solute compared to the solvent
by a
-
retention time The time taken for
gas 1 liquid
a to pass
through the column
-
adsorption - The attraction of an atom to the surface of another substance
absorption - when atoms enter another bunny phase such as a solid 1 liquid
polar t time to travel
Thin
layer chromatography ( TLC)
,
up chromatogram
→
quick and inexpensive
→
indicates how components are in a mixture
many .
→
TLC
plate coated with a thin layer of solid Absorbart substance ( e.g , silica)
→
Absorbant the
is
stationary phase
different components different affinities for
→
have the absorbent and bird with
differing strengths
to its surface
→
adsorption process where solid silica holds different substances to its surface
-
Retention factor (Rf) = distance moved by the component
distance moved by the solvent front
→
The Sowles are separated differences in their Attraction to the
by the
stationary
and the mobile phase ( one will have a high adsorption property) .
phase polar ( the phase)
→
one adsorb are and the other non polar ⇒ souses separate by polarity
-
→
Separation measured difference far the
by measuring the in how solute travels compared
to ( Retardation factor)
the solvent or
by how
quickly the saute travels
through the
chromatograph ( Retention time)
→ values can be compared to known values of grandam solutions to
identify the solute
Mobile phase polar ( alkane) / solvent ( water 1 alcohol)
tonAdsorbent
°
- -
polar
surface ( silica 1 Aluminium Oni de)
stationary phase
°
Explain how souses are separated in TLC .
↳ with a non -
polar mobile phase
→
polar stationary phase → T polarity of solute r adsorption & will travel slowest up
chromatograph
→
non have t adsorption to
polar mobile phase → non polar so hues
stationary
-
-
phase but will be t sombre in the morale phase so wi u travel
quicker up the
chromatograph .
↳ with a polar mobile phase
→
t commonly used
t whilst less polar molecules
polarity of the
→
solute it travels up the
, quicker chromatograph
would travel Rowen .
, Industry stationary :
Sia IA Koz
-
,
mobile -
solvent
Colourless Samples view under UN
light
°
:
.
°
In fume cupboard :
A A Stained
.
.
by his hydria
Iodine crystals beaker and cover Iz sublimes Iz vapour stains molecules
organic
°
. : Add to .
, spots appear as
① Take a TLC plate & draw the base line with a pencil ( 1cm from one end)
② Use a capillary tube to spot your sample onto the base line
③ Pour some solvent into a breaker (O . S on depth approx .
)
⑨ Place the plate into the beaker and cover with a watch
glass
⑤ Allow the solvent to rise up the plate until it's 1cm from the top a-
watch glass
⑥ Remove the plate and mark the solvent front with a pencil
⑦ Circle
⑧ Use w/
Any visible spots
locating agent (e.g .
ninhydrin ) to show spots
⇒
peeing
-
#
-
Tlc plate
seamer
sowenr
+ silica
gel
Spor or
substance
Gas
→
chromatography
Separating &
identifying volatile organic compounds present in a mixture .
→
stationary phase injector
Tb adsorb Port
is a .
p .
liquid -
flow →
capillary column has
F⑤⑥z→F/#aer
ed controller
onto an inert solid
liq Stationary phase
. adsorbed
support . .
→
components slow down
↳
The mobile phase is
as ineraa with the cia
they .
Y ihnairwncaryrionr ?
as such column
demurrer stationary phase
→ f soluble in stationary
column oven
I
→
Volatile t speed
mixture
injected packed with powder phase ,
it moves
→
eluent carries →
Separated based on
carrier gas
components (carrier ( me Nz ,
→
inert gas solubility
,
gas )
°
Mobile phase :
Inert gas ,
stationary phase high boiling :
liquid adsorbed onto
An inert solid support
Explain how the solutes are separated in Gas chromatography ?
→
solutes separated by their solubility in s .
P . and their B P . .
compounds with t solubility and PB Ps will travel
→
. slowest as most attracted whilst least soluble and d B . P
will pass
through the quickest .
Retention Time time from sample injected to when its recorded detector
by
→
when is the
↳ can
compare database to
to a
identify components
peak integrations → area under each peak , used to determine the core . of components
in the sample .
↳
plot a calibration curve ( peak area vs . conc .
) ⇒ external calibration
what affects retention time ?
solubility ( t soluble t time)
-
,
boiling point ( t BP 9 time condensed than gas)
-
,
as a
temperature ( 9 Hmp r time evaporated)
-
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller sram123. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £13.39. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
52510 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now