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1 year ago

What can happen if the level of the developing liquid is higher than the applied spots in the tlc analysis?

1 answer:

7 0

If the solvent level in the developing jar is deeper than the origin (spotting line) of the TLC plate, the solvent will dissolve the compounds into the solvent reservoir instead of allowing them to move up the plate by capillary action. Thus, you will not see spots after the plate is developed.

What is Thin Layer Chromatography (TLC)?

TLC is a simple, quick, and inexpensive procedure that gives the chemist a quick answer as to how many components are in a mixture.
TLC is also used to support the identity of a compound in a mixture when the Rf of a compound is compared with the Rf of a known compound.
A TLC plate is a sheet of glass, metal, or plastic which is coated with a thin layer of a solid adsorbent (usually silica or alumina). A small amount of the mixture to be analysed is spotted near the bottom of this plate.
The TLC plate is then placed in a shallow pool of a solvent in a developing chamber so that only the very bottom of the plate is in the liquid. This liquid, or the eluent, is the mobile phase, and it slowly rises up the TLC plate by capillary action.
As the solvent moves past the spot that was applied, an equilibrium is established for each component of the mixture between the molecules of that component which are adsorbed on the solid and the molecules which are in solution.
In principle, the components will differ in solubility and in the strength of their adsorption to the adsorbent and some components will be carried farther up the plate than others. When the solvent has reached the top of the plate, the plate is removed from the developing chamber, dried, and the separated components of the mixture are visualized. If the compounds are coloured, visualization is straightforward.
Usually the compounds are not coloured, so a UV lamp is used to visualize the plates. The plate itself contains a fluorescent dye which glows everywhere except where an organic compound is on the plate.

To learn more about TLC: brainly.com/question/13483325

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2) If 100.0 J of heat are added to 20.0 g of water at 30.0°C, what will be the final

anzhelika [568]

The final temperature of the water will be 31.2 °C... i don’t know the second one sorry :(

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2 years ago

If the reduction reaction has a reduction potential of 0.1 V, and the oxidation reaction has a reduction potential of -0.4V, and

aleksley [76]

Answer : The value of ΔG expressed in terms of F is, -1 F

Explanation :

First we have to calculate the standard electrode potential of the cell.

$E^o=E^o_{cathode}-E^o_{anode}$

or,

$E^o=E^o_{reduction}-E^o_{oxidation}$

$E^o=(0.1V)-(-0.4V)=+0.5V$

Now we have to calculate the standard cell potential.

Formula used :

$\Delta G^o=-nFE^o$

where,

$\Delta G^o$ = Gibbs free energy = ?

n = number of electrons = 2

F = Faraday constant

$E^o$ = standard e.m.f of cell = +0.5 V

Now put all the given values in this formula, we get the Gibbs free energy.

$\Delta G^o=-(2\times F\times 0.5)$

$\Delta G^o=-1F$

Therefore, the value of ΔG expressed in terms of F is, -1 F

5 0

3 years ago

Ionic compounds are typically between a

barxatty [35]

It starts with a cation and ends with a nonmetal anion. To recap, cations are your positively charged elements and anions are negatively change and usually with the ending “ide”. For example, potassium a metal and chlorine a nonmetal (KCl) would form the word potassium chloride.

8 0

3 years ago

Classify each one of the following as pure substances or mixtures:

vova2212 [387]

Please refer to the attachment for a complete classification of your specified matter.

Download docx

6 0

3 years ago

Read 2 more answers

List several other words that are formed using the prefix mon or mono what do these words have in common

UkoKoshka [18]

Answer:

1) Monochrome

2) Monocot

3) Monosaccharide

4) Monounsaturated

5) Monoxide

Explanation:

The prefix mono or mon is of Greek origin and it means single, lone or one.

From the meaning of the words we can tell that they have something in common:

1) Monochrome: This refers to an artwork, a painting or drawing that has just one color.

2) Monocot: This is a type of flowering plant that has a single embryo and a single cotyledon.

3) Monosaccharide: This is a type of simple sugar that contains one sugar unit that cannot be split.

4) Monounsaturated: This refers to a molecule that contains one double or triple bond.

5) Monoxide: This refers to a form of oxide that contains only one oxygen atom.

From the definitions above, all the words mean having only one or a single item.

That is what they have in common.

7 0

2 years ago