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alexandr402 [8]
3 years ago
13

Select the correct answer.

Chemistry
2 answers:
sergejj [24]3 years ago
4 0
D.) black text on a yellow background. There is much more contrast in the colors black and yellow than the other choices.
Igoryamba3 years ago
4 0
D black text on yellow background
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Answer:

D

Explanation:

because the rest don’t make any sense

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Consider the following equilibrium reaction having gaseous reactants and products.4HCl + O2 ⇌ 2H2O + Cl2Which of the following w
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According to what is known about chemical equilibrium and Le Chatelier's principle, when you increase the amount of the reactants, the reaction will be moved to the products, this is because, the most reactants we have the most products we can produce.

From the given choices, the one that goes according to this reason is the third one: The volume of water vapor increases.

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1 year ago
What is paper chromatography? Calculate the Rr value of a colored dye that traveled 52 mm on a chromatography strip while the so
Karo-lina-s [1.5K]

Answer:

Paper chromatography is a basic technique of chromatography. It consist in the separation of the mixe components using a solvent.

Explanation:

Paper chromatography is a basic technique of chromatography. It consists in the separation of the mixed components using a solvent.

Paper chromatography consists of put some dot of the mix using a glass capillary into a specialized paper, generally made of cellulose, this is called a stationary phase.

Then you put this paper into a camera of glass named, chromatography camera, where previously contain a solvent. The solvent also know as a mobile phase, the type can be defined before the test and involves a study of the kind of the mix, and the compound you want to separate.

The chromatography camera has to be closed all the time during the test, and you can't move at all because the movement of the solvent can alternate the result.

Very often, the solution of the solvent is a mix of different liquid substances with different polarities.

When the stationary phase put into the camera, the solvent starts to move up over the paper, until the separation of the compounds is observable.

the Rf is a value who relates the move of the mobile phase with the move of the distance traveled by the substance tested.

To undersant the paper chromatography, you can watch the images attached.

The first is an image of the chromatography camera.

The second one is an image of a cellulose paper after the chromatography is done. You can watch the dots who indicates the traveling of the compound across the paper.

The third one can show you the evolutions of paper chromatography, from the beginning to the end.

To calculate the Rf value you have to use the equation:

Rf = distance traveled by the substance/distance traveled by the solvent/

<u>Rf = 52mm/81mm =0.64</u>

<u></u>

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Please help!! What is this
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