OCR CHEMISTRY A - Transition Metals - detailed notes + practice questions
OCR Chemistry A Chapter 20-21 Acids, bases, pH and buffers Powerpoint
A level chemistry OCR chapter 29 notes
All for this textbook (21)
Written for
A/AS Level
OCR
Chemistry A
Organic chemistry
All documents for this subject (33)
Seller
Follow
rebeccamoore2
Content preview
Chapter 29
29.1 CHROMATOGRAPHY AND FUNCTIONAL GROUP ANALYSIS
What is the purpose of chromatography? To separate individual components from a
mixture of substances
What are the two phases called? Stationary and mobile phase
What is the stationary phase? It does not move and is normally a solid or a
liquid supported on a solid- the adsorbent
What is the mobile phase? It does move, and is normally a liquid or gas
(solvent)
What is the surface in TLC? A plate which is usually a plastic sheet or glass,
coated with a thin layer of a solid adsorbent
substance, usually silica
The differing components in the mixture have Affinities for the absorbent and bind with
different what? differing strengths to its surface
What is adsorption? The process by which the solid silica holds the
different substances in the mixture to its surface.
How do you carry out TLC?
How to get sample?
Where to put it?
How to prepare tank?
During it?
When to remove it?
After it?
How are chromatograms analysed? By calculating retention factor for each
component. Each component can be identified
by comparing its Rf value with known values
recorded using the same system and absorbent.
, Chapter 29
Rf equation? Distance moves by the component
Distance moved by the solvent front
What is gas chromatography used for? Separating and identifying volatile organic
compounds present in a mixture
What is the stationary phase? A high boiling liquid adsorbed onto an inert
solid support.
What is the mobile phase? An inert carrier gas such as helium or neon
Explain how gas chromatography works
Retention time The time taken for each component to travel
through the column
Retention times can be used to what? Identify the components present in the sample
by comparing these to retention times for known
components
Peak integrations Areas under each peak
Peak integrations can be used to what? Determine the concentrations of components in
the sample
How do you determine the concentration of a
component in a sample in a practical way?
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 or Stuvia-credit 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 rebeccamoore2. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.86. You're not tied to anything after your purchase.