100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
Analytical Chemistry 1 (correct answers) $15.49   Add to cart
Quickly navigate to
Preview
  2.  
  3. Analytical Chemistry 1
  4.  
  5. Analytical Chemistry 1

Exam (elaborations)

Analytical Chemistry 1 (correct answers)
 5 views  0 purchase
  • Course
  • Analytical Chemistry 1
  • Institution
  • Analytical Chemistry 1

Why separate compounds? correct answers 1- to isolate or concentrate components from a mixture 2- to separate a component from other species that would interfere in the analysis methods of separation correct answers extraction; crystallization; distillation; chromatography extraction correc...

[Show more]

Preview 2 out of 6  pages

Document information

  • May 3, 2023
  • 6
  • 2022/2023
  • Exam (elaborations)
  • Questions & answers

Subjects

  • why separate compounds correct answers 1 to isolate or concentrate components from a mixture 2 to separate a component from other species that would interfere in the analysis

Written for

  • Analytical Chemistry 1
All documents for this subject (1)

Seller

avatar-seller
Governor001

Content preview

Analytical Chemistry 1 (correct answers)
Why separate compounds? correct answers 1- to isolate or concentrate components
from a mixture
2- to separate a component from other species that would interfere in the analysis

methods of separation correct answers extraction; crystallization; distillation;
chromatography

extraction correct answers method of separation; transfer of a solute from one phase to
another; uses two immiscible liquids

partition coefficient (extraction) correct answers k=[s2]/[s1]; used in solvent extraction

q (extraction) correct answers = V1/(KV2+V1)(^n); fraction of moles in S1

chromatography correct answers method of separation; based on different distrubtion
coefficients between two phases; one phase is stationary and the other is mobile

mobile phase (chromatography) correct answers gas or liquid

stationary phase (chromatography) correct answers liquid or solid

adsorption chromatography correct answers based on solute adsorption on surface of
stationary phase

partition chromatography correct answers based on solute dissolving into stationary
liquid

ion-exchange chromatography correct answers separation based on charge

size exclusion chromatography correct answers separation based on molecular size

adjusted retention time correct answers T(retention)-T(mobile phase)

Relative Retention correct answers T'(r2)/T'(r1); higher ratio means more separation

partition coefficient (chromatography) correct answers K= (Cs)/(Cm)

capacity factor (chromatography) correct answers k'; measure of retention; =K(Vs)/(Vm)
=Ms/Mm =Ts/Tm =(Tr-Tm)/Tm

q (chromatography) correct answers =(molesm)/(moless+molesm) =1/(1+k'); fraction of
solute in mobile phase

rate of travel of solute through column correct answers =V(velocity)*q(mobile)

, retention time (Tr) correct answers time it takes solute to go from beginning to end of
column; =L/(rate of solute travel) =Tm(1+(KVs/Vm)) =Tm(1+k')

retention volume (Vr) correct answers =Vm(1+(KVs/Vm)) =Vm+KVs

factors affecting separation correct answers difference in retention time
peak widths

gaussian peak correct answers W1/2= 2.35(standard deviation) W=4(standard
deviation)

resolution (retention) of two solutes correct answers higher R=better separation; R>1 is
good

plate theory (chromatography) correct answers separation occurs in discrete stages;
more stages=more plates=better separation

theoretical plates (N) correct answers indicates how good a column is for separation;
increasing retention time increases N

N versus resolution correct answers R is proportional to sqrt(N); N is required to obtain
a certain resolution

Plate Height correct answers height equivalent of a theoretical plate- HETP
constant of proportionality between the band width and the distance it has traveled

Van Deemter Equation correct answers H = A + B/u + Cu
u = linear velocity
A = eddy diffusion
B = molecular diffusion
C = mass transfer
-explains band broadening

Eddy Diffusion correct answers A- constant term
-depends on solute paths, size of particles; in packed stationary phase; increases with
porosity

Longitudinal Diffusion correct answers B- varies
-band broadening caused by diffusion of solute from center of band to edge of band
(higher to lower concentration)
-increasing velocity decreases effect

Resistance to Mass Transfer correct answers C- varies
-band broadening caused by time taken for solute to equilibrate between stationary and
mobile phase

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

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

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

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 Governor001. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $15.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

75323 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$15.49
  • (0)
  Add to cart