Docsity
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Docsity AI
Docsity AI
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Thin Layer Chromatography –Questions/Answers, Exams of Nursing

Chamberlain College of NursingNursing

Thin Layer Chromatography –Questions/Answers

Typology: Exams

2024/2025

Available from 06/19/2025

may-blessed
may-blessed 🇺🇸

4.1

(8)

31K documents

1 / 12

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Thin Layer Chromatography –Questions/Answers
____ a method of separating mixtures into their pure components ✔ Ans -
Chromatography
chromatography: a method of _____ ✔ Ans - separating mixtures into their
pure component
Chromatography separates mixtures because the ____ between the various
components of the mixture and the stationary phase are different ✔ Ans -
intermolecular attractions
Chromatography separates mixtures because the intermolecular interactions
between the ____ ✔ Ans - various components of the mixture and the
stationary phase are different
Chromatography is a method of separation using a ___ and a ____ ✔ Ans -
stationary phase; mobile phase
separation occurs as the mobile phase ____ the stationary phase ✔ Ans - passes
over
the mobile phase can be ___ or ___ ✔ Ans - liquid; gas
the stationary phase can be ___ or ___ ✔ Ans - solid; liquid
Chromatography-Basic Principle: same basic principle as TLC but now ____ of
pressure (_____) to ___ compounds ✔ Ans - use gravity; medium to high; elute
Chromatography is both a ____ and ____ method ✔ Ans - qualitative;
quantitative
Chromatography is used for _____ the course of a reaction ✔ Ans - monitoring
Chromatography is used for monitoring ____ ✔ Ans - the course of a reaction
pf3
pf4
pf5
pf8
pf9
pfa

Partial preview of the text

Download Thin Layer Chromatography –Questions/Answers and more Exams Nursing in PDF only on Docsity!

Thin Layer Chromatography –Questions/Answers

____ a method of separating mixtures into their pure components ✔Ans - Chromatography chromatography: a method of _____ ✔Ans - separating mixtures into their pure component Chromatography separates mixtures because the ____ between the various components of the mixture and the stationary phase are different ✔Ans - intermolecular attractions Chromatography separates mixtures because the intermolecular interactions between the ____ ✔Ans - various components of the mixture and the stationary phase are different Chromatography is a method of separation using a ___ and a ____ ✔Ans - stationary phase; mobile phase separation occurs as the mobile phase ____ the stationary phase ✔Ans - passes over the mobile phase can be ___ or ___ ✔Ans - liquid; gas the stationary phase can be ___ or ___ ✔Ans - solid; liquid Chromatography-Basic Principle: same basic principle as TLC but now ____ of pressure (_____) to ___ compounds ✔Ans - use gravity; medium to high; elute Chromatography is both a ____ and ____ method ✔Ans - qualitative; quantitative Chromatography is used for _____ the course of a reaction ✔Ans - monitoring Chromatography is used for monitoring ____ ✔Ans - the course of a reaction

3 types of chromatography used for monitoring the course of a reaction ✔Ans - thin layer chromatography; gas chromatography; high performance liquid chromatography what does TLC stand for ✔Ans - thin layer chromatography what does GC stand for ✔Ans - gas chromatography what does HPLC stand for ✔Ans - high performance liquid chromatography chromatography is used for _____ the components of a reaction ✔Ans - isolating what methods of chromatography are used for isolating the components of a reaction ✔Ans - column chromatography; prep HPLC; Prep TLC Chromatography is both a qualitative and quantitative method used for ___, ___ and ___ ✔Ans - 1) monitoring the course of a reaction

  1. isolating the components of a reaction
  2. assisting in the identification of a compound In liquid chromotagraphy ____ is established ✔Ans - equilibrium equation for chemical equilibrium is established and can be represented by the following equation ✔Ans - in the equation for chemical equilibrium what does Xm and Xs stand for ✔Ans
  • the concentrations of solute molecules in the mobile phase and the stationary phase in the equation for chemical equilibrium what does Sm and Ss stand for ✔Ans - Sm and Ss are for the solvent molecule concentrations in the equation for chemical equilibrium what does the value K represent ✔Ans
  • the distribution coefficient or equilibrium between the solute and solvent molecules and between the mobile and stationary phases

Order of Elution: polar compounds are strongly retained on the polar stationary phase and therefore are ____ from the ___ filled with ____ ✔Ans - eluted; chromatographic columns; polar stationary phase Order of Elution: _____ are strongly retained on _____ and therefore are eluted late from the chromatographic column filled with nonpolar (so called ___) phase ✔Ans - nonpolar compounds; nonpolar stationary phases; reversed nonpolar compounds are strongly retained on nonpolar stationary phases and therefore eluted late from the chromatographic column filled with _____ ✔Ans - nonpolar (so called reversed) phase Draw column chromatography where A is more polar than B. ✔Ans - Draw thin layer chromatography where A is more polar than B ✔Ans - (Mobil phase moves upwards) If A is more polar than B. ___ will elute later from a column with polar stationary phase in column chromatography and will _____ with a polar stationary phase (having a lower ____) ✔Ans - A; stay at the origin of the thin layer chromatography plate; Rf what does Rf stand for ✔Ans - retention factor if something has a higher retention factor then in mobile phase it sill ___ ✔Ans

  • not move as far If the solvent moved 100mm and A moved 60mm what is the retention factor ✔Ans - How do you make a capillary pipet ✔Ans - take a capillary tube. Place middle part in flame, rotate until soft. Remove from flame and pull. Score lightly in center of pulled section. Break in half to give two pipets See back page for question?

1st: not polar enough 2nd: satisfactory 3rd: too polar ✔Ans - Which of these solvents is satisfactory? See next page for question Rf(compound 1)=22/65=0. Rf(compound 2)=50/65=0.77 ✔Ans - What is Rf compound 1? What is Rf compound 2? _____ spots are colored ✔Ans - visualized colorless spots require ✔Ans - I2 vapor; various oxidizing stains such as KMnO4, MoO3, fluorescent indicator in stationary phase (visualized with UV light), special spray reagents What does it mean when Rf=1 ✔Ans - spots travel with solvent front Rf=0 what does it mean ✔Ans - spot doesn't move off baseline, undesirable range of Rf values ✔Ans - Rf from 0 to 1

  1. identification
  2. monitoring reactions Why do A, B and C separation ✔Ans - 1) chemical nature of A, B, C
  3. type of stationary phase
  4. mobile phase polarity Different types of chemical nature of A, B, and C which affect separation of compounds. ✔Ans - 1) bond-dipoles and polarity
  5. hydrogen bonding
  6. presence of acidic hydrogens
  7. ionic bonds or salts
  8. proportion of "polarity" to "grease" What is adsorption? ✔Ans - It is a surface phenomenon. Molecules 'stick' to the surface of a polar solid. "They are said to be absorbed on the surface." adsorption is not the same as ___ ✔Ans - absorption Adsorption Chromatography: stationary phase is a ____ ✔Ans - solid absorbent 3 things which may be used as a solid absorbent ✔Ans - Silica gel (SiO); C18; Alumina (Al2O3) In normal phase chromatography the ___ compound moves faster because ____ ✔Ans - least polar; it interacts with the stationary phase to a lesser extent Normal Phase Chromatography: the least polar compound has a ____ retention time and therefore travels ____ the plate. It has a ___ Rf ✔Ans - shorter; farther up; high ___ and ___ are common polar stationary phases that will interact strongly via electrostatic interactions with molecules that are ____ ✔Ans - SiO2; Al2O3; polar ____ is kinda like the opposite of normal-phase chromatography ✔Ans - reverse-phase chromatography

In reverse-phase chromatogrpahy ____ interacts strongly with greasy compounds containing lots of saturated and unsaturated _____ ✔Ans - C18 backbone; hydrocarbon functionalities R(CH2)nCh3 and other hydrocarbon groups are very ____ functional groups and thus stick to the _____ ,resulting in a Rf in reverse phase chromatography ✔Ans - nonpolar; nonpolar stationary phase; Rf In reverse phase chromatography the ____ moves faster, has a____ retention time, travels ___ and has a Rf ✔Ans - polar compound; shorter; farther; higher adsorption works because of ____ ✔Ans - electrostatic attraction partitioning applies to ___ and ____ chromatography ✔Ans - liquid-liquid; gas- liquid ____ applies to liquid-liquid and gas-liquid chromatography ✔Ans - partitioning in ____ compounds distribute between the two immiscible liquid phases ✔Ans - paritioning Solubility differences cause ___ ✔Ans - separation _____ cause separation ✔Ans - solubility separation The value ___represents the distribution coefficient or equilibrium of a solute A between the ____ ✔Ans - Kp; the two systems Kp=A1/A2 where A1 is amount of A in phase 1 and A 2 is amount of A in phase 2 bond dipoles depend on ___, ___ and ___ ✔Ans - bond length; charge separation; electronegativity difference a molecular dipole moment is the ____ ✔Ans - vector sum of the bond dipole moments

photosynthetic pigments contained in spinach leaves belong to two classes ____ and ____ ✔Ans - cartenoids; chlorophylls 2 types of cartenoids ✔Ans - cartene; xanthophylls 2 types of chlorophylls in experiment ✔Ans - cchlorophyll a and b _____ is the primary pigment that transforms the energy of sunlight into chemical energy oters are ____ ✔Ans - chlorophyll a; accessory pigments what do accessory pigments do ✔Ans - help efficiently harvest the light and deliver protons to chlorophyll a _____ via a redox reaction donates an electron into an electron transport chain ✔Ans - accessory pigments ____ is chlorophyll lacking the central magnesium ion and serves as a primary electron acceptor and helps initiate the ETC in photosynthesis ✔Ans - phenophytin pheophytin is ____ lacking the _____. It serves as a primary electron acceptor and helps to ___ in photosynthesis ✔Ans - chlorophyll; magnesium ion; initiate the electron transport chain Chlorophyll a has a ____ where chlorophyll b has an ____ ✔Ans - methyl group; aldehyde functional group chlorophyll ___ is slightly more polar than chlorophyll __ ✔Ans - b; a ____ is a hydrocarbon and is therefore very lipophilic and nonpolar ✔Ans - beta-Carotene what is your solvent front? ✔Ans - pretty much how high up the solvent trveled up the paper what might change Rf of same compound ✔Ans - type of solvent u use;

temperature when does stationary phase occur for substance ✔Ans - when it is stuck to paper nd not moving when does mobile phase occur for a substance ✔Ans - when it is free moving, not stuck to paper molecules are constantally moving back and forth between free and absorbed stages. What effects this equilibrium ✔Ans - 1) polarity and size of moleculle

  1. polarity of the stationary phase
  2. polarity of the solvent list following from eluted first to last chlorophyll b, chlorophyll a, beta carotene, violaxanthan, zeaxanthin, lutein ✔Ans - beta carotene; chlorophyll a; chlorophyll b; lutein; zeaxanthin; violaxanthan ethanol chemical formula ✔Ans - CH3Ch2OH ethyl acetate chemical formula ✔Ans - C4H8O hexane chemical formula ✔Ans - C6H isopropanol chemical formula ✔Ans - C3H8O silicon dioxide chemical formula ✔Ans - SiO potassium permanganate chemical formula ✔Ans - KMnO what is elute of part 1 ✔Ans - (isopropanol/water 6:1) what is elute part 2 ✔Ans - hexane/ethyl acetate (1:1) Why do you add ethanol to the spinach leaves only to extract the ethanol after mixing ✔Ans - because the compounds we are interested in are relatively