Find the volume. mass is 9.75 g and the density is 15.6 g/cm3

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/

Rf = 52mm/81mm =0.64

3 0

3 years ago

Imagine that Ana has a block made of pure gold. If she cuts this block into two equal pieces, pick the statement that best descr

dimaraw [331]

Answer : The correct statement is:

The density of each piece is the same as that of the original block.

Explanation :

Intensive property : It is defined as a property of substance which does not change as the amount of substance changes.

Examples: Temperature, refractive index, density, hardness, etc.

According to question, if Ana has a block made of pure gold and she cuts this block into two equal pieces then the density of each piece is the same as that of the original block because density is an intensive property that does not changes until and unless material is changed.

That means density remains same as that of the original piece.

Hence, the correct statement is the density of each piece is the same as that of the original block.

6 0

3 years ago

How many grams of sodium sulfide can be produced when 45.3 g Na react with 105 g S?

RoseWind [281]

The chemical reaction would be as follows:

2Na + S → Na2S

We are given the amount of the reactants to be used in the reaction. We use these to calculate the amount of product. We do as follows:

45.3 g Na ( 1 mol / 22.99 g ) = 1.97 mol Na
105 g S ( 1 mol / 32.06 g ) = 3.28 mol S

The limiting reactant would be Na. We calculate as follows:

1.97 mol Na ( 1 mol Na2S / 2 mol Na ) (78.04 g / mol ) = 76.87 g Na2S produced

8 0

3 years ago

The last element in any period always has:

brilliants [131]

Answer: The correct option is The properties of a noble gas.

Explanation: There are 7 periods in the periodic table.

The last element of each period are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) and Ununoctium (Uuo).

The electronic configuration for Helium is $1s^2$ . For He, The outermost electrons are 2.

The electronic configuration for all the other elements is $ns^2ns^6$ ( where, n = 2, 3, 4, 5, 6 and 7 respectively). For all the other gases, the outermost electrons are 8.