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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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Complimentary angles are the right answer

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2 years ago

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Isotopes of the same element have the same chemical properties because they have the same number of

Sloan [31]

Answer:

PROTONS

Explanation:

Isotopes of the same element have the same chemical properties because they have the same number of PROTONS (and electrons).

4 0

3 years ago

A histidine is involved in an interaction with a glutamic acid that stabilizes the charged form of the histidine, such that the

Greeley [361]

Answer:

pKa of the histidine = 9.67

Explanation:

The relation between standard Gibbs energy and equilibrium constant is shown below as:

$\Delta{G^0} =-RT \ln \frac{[His]}{[His+]}$

R is Gas constant having value = 0.008314 kJ / K mol

Given temperature, T = 293 K

Given, $\Delta{G^0}=15\ kJ/mol$

So, Applying in the equation as:-

$15\ kJ/mol=-0.008314\ kJ/Kmol\times 293\ K\times \ln \frac{[His]}{[His+]}$

Thus,

$15\ kJ/mol=-0.008314\ kJ/Kmol\times 293\ K\times \ln \frac{[His]}{[His+]}$

$\frac{[His]}{[His+]}=e^{\frac{15}{-0.008314\times 293}$

$\frac{[His]}{[His+]}=0.00211$

Also, considering:-

$pH=pKa+log\frac{[His]}{[His+]}$

Given that:- pH = 7.0

So, $7.0=pKa+log0.00211$

pKa of the histidine = 9.67

8 0

2 years ago

8.5ml of a sample of sea water solution was added to a 44.317g evaporating dish the combination weighted 52.987g after evaporati

Ratling [72]

Answer: There is no question, but we can calculate a couple of items:

Density of sea water sample = (52.987g-44.317g)/8.5ml

Inorganic content of sample (mostly salts) = (44.599g-44.317g)/(52.987g-44.317g) x 100% = percent inorganics in water sample

Explanation:

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2 years ago

Type the correct answer in the box.

IgorLugansk [536]

Answer:

a= In scientific notation

6.96000×10⁵ Km

b =In expanded notation

0.00019 mm

Explanation:

Given data:

Radius of sun = 696000 Km

size of bacterial cell = 1.9 ×10⁻⁴ mm

Radius of sun in scientific notation = ?

Size of bacterial cell in expanded notation = ?

Solution:

Scientific notation is the way to express the large value in short form.

The number in scientific notation have two parts.

. The digits (decimal point will place after first digit)

× 10 ( the power which put the decimal point where it should be)

for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³

Radius of sun:

696000 Km

In scientific notation

6.96000 × 10⁵ Km

The expanded notation is standard notation of writing the numerical values which is normal way. The numbers are written as they are, without the power of 10.

Size of bacterial cell:

1.9 ×10⁻⁴ mm

In expanded notation

1.9/ 10000 = 0.00019 mm

3 0

3 years ago