Remember that as soon as yourun a TLC plating lab you have twp phases, thestationary phase displayed as this blue silica gel onthe plate and a cell phone phase. The cell phone spaceis a solvent that's less polar 보다 thesolid stationary phase. Silica gelatin is very, really polar. Let's say that you had actually aplate the looked something choose this. You had actually initiallyspotted 2 compounds. We'll call them A andcompound B. And then what you observed on the plate wasthat your mobile phase had actually traveled up to about here, Ahad traveled to around here, and B had traveled this far. However what does the really mean? How have the right to we evenreport these values? The way we'd report lock if wewere composing up a lab report or creating amanuscript, you'd require something known as theretardation factor, also known as the retentionfactor or RF for short. RF is same to thedistance travel by solute over the distancetraveled by the solvent. For this reason the an initial stepyou have to do is measure up these distancesfor the various compounds and likewise for the solvent, alsoknown as the mobile phase. For this reason let's placed a rulernext come our TLC plate, much like you would ifyou were sitting in lab. We'll say that this is 1 unit,2 units, 3 units, and also 4 units. Therefore we deserve to measure thedistance the A has actually traveled, and also that's from the startingline come the center of the spot. That's 2 units. And for compound B, againfrom the beginning line to the facility of thespot, that's 3 units. And for the solvent, thestarting heat to this end up line, that is 4 units. Therefore let's plug thatinto our equation. If we want tosolve RF that A, you require the distancetraveled by compound A end the distancetraveled by the solvent, for this reason let's speak A end S.Here, that would certainly be equal to 2 end 4, andthe convention is come report this valuesas decimal points, for this reason we'll say the this is 0.5. Now, we'll perform the samefor compound B. RF the B is same to distance traveled byB over street traveled by S. In this case, that's equalto 3 over 4, or 0.75. Therefore what have the right to we call aboutthese 2 compounds? If we remember from talkingabout the mobile phase and stationary phase, compoundsthat take trip really much must be an ext attractedto the mobile phase, and therefore are much less polar. Therefore we can say the compound B isless polar and also travels faster. The opposite istrue for compound A. Since this doesn'tmove as much, it's more attracted tothe polar silica gel, and hence it's an ext polar thancompound B and travels slower. Think about it prefer it's gettingstuck in the stationary phase and also doesn't really wantto relocate away from it. So over there we've doneour an initial example. Let's do another one. In this example, we have the right to see thatour initial reaction mixture separated into fourdifferent compounds. Let's label theseas A through D, through A gift the orangespot, B together the yellow one, C as the green one, andD together the violet one. Again, we'll use the sameprocess that we offered earlier. So the first stepis to take it a ruler and put it next your TLC plate. This is 1 unit, 2units, 3, 4, 5, and also 6. For this reason let's calculatethe RF that A. This is equal to thedistance travel by A end the distancetraveled through the solvent, so we must measure these. First, we can see the A hastraveled 1 unit, same to 1, and the solvent hastraveled about 6 units. So we'll speak that's1 end 6 then. Let's convert that todecimals and also you have 0.17. We have the right to do the very same foreach these compounds. Next, we'll takeB. This is again same to B end S, i beg your pardon equalsthis street is about 3 units. Therefore we have actually 3 over 6,which is same to 0.50. Next, we'll measurethis because that C. The RF the C is same to thedistance traveled by C end the distance traveledby S, which equals-- street traveled by C is 4-- sothat's walk to be 4 end 6, i beg your pardon is equal to 0.66. And lastly because that D,again we'll have to measure the street traveledby D over street traveled by S. In this case,this street is 5, so this would certainly be 5 over6, i m sorry is same to 0.83. Currently what deserve to we speak aboutthese as whole trends? Again, we claimed that compoundsthat take trip really, really much are nice nonpolar,and compounds the don't travelvery far at every are much more attracted tothe stationary phase and also hence are more polar. For this reason if us look atthese RFs, we can show that there reallyis a trend here. Compounds with a smallerRF are an ext polar, because they're more attractedto the stationary phase. And also compounds v abigger RF are less polar, due to the fact that they're much more attractedto the mobile phase. Let's review quicklywhat we've learned today.


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We learned just how to calculatethe RF value, additionally known together the retention factoror retardation factor, and also how you would report thatwhen presenting in a rap report or in the literature. We showed that compoundswith big RFs are less polar, and also compounds with prettysmall RFs are much more polar.