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3 years ago

what would you observe if you used a ballpoint pen instead of a pencil to mark the chromatography paper?

Chemistry

1 answer:

sveticcg [70]3 years ago

3 0

Answer:

It basically messes up the results

Explanation:

Pen ink consists of resins, pigments and other colouring dyes dissolved in appropriate solvents like propylene glycol, propyl alcohol and some other ethers. If the ball point pen is used to mark on the chromatography paper then these pigments will also move along with the solvent and interfere with the spots of our analyte.

If you use a ball point pen when doing a chromatogram, then the ink would separate as it is a mixture and run down the paper.

Graphite, or pencil lead however, is not an organic material and therefore will not be affected by common organic solvents used for thin-layer chromatography. Pen ink on the other hand will be readily absorbed by the solvent and will move up the plate.

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ILL GIVE YOU BRAINLIST !!! HAVE TO GET IT RIGHT !!

inysia [295]

Answer: The 3rd and 6th bullet point is the quantitative data.

Explanation: Quantitative data is expressed by NUMBERS and Qualitative data is expressed by WORDS. The 3rd and 6th one is correct because they both use numbers to compare how much time hummingbirds spent feeding on nectar.

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3 years ago

Choose the correct statement. The cathode is the electrode where the oxidation takes place. Both oxidation and reduction may tak

gregori [183]

Answer:

The cathode is the electrode where the reduction takes place.

Explanation:

Cell has three components:

an electrolyte and two electrodes which is a cathode and an anode.

Electrolyte is usually solution of the water or other solvents in which the ions are dissolved.

In electrolytic cell:

Negatively charged electrode is the cathode where the process of reduction takes place.

Positively charged electrode is the anode where the process of oxidation takes place.

In galvanic cell:

Positively charged electrode is the cathode where the process of reduction takes place.

Negatively charged electrode is the anode where the process of oxidation takes place.

So, the correct answer is - The cathode is the electrode where the reduction takes place.

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3 years ago

What is Cytokine Release Syndrome (CRS)

laila [671]

Answer:

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Explanation:

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3 years ago

Calculate the molality of 75.0 grams of MgCl2 (molar mass=95.21 g/mol) dissolved in 500.0 g of solvent.

nordsb [41]

Answer: The molality of magnesium chloride is 1.58 m

Explanation:

To calculate the molality of solution, we use the equation:

$\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

$m_{solute}$ = Given mass of solute (magnesium chloride) = 75.0

$M_{solute}$ = Molar mass of solute (magnesium chloride) = 95.21 g/mol

$W_{solvent}$ = Mass of solvent = 500.0 g

Putting values in above equation, we get:

$\text{Molality of }MgCl_2=\frac{75.0\times 1000}{95.21\times 500.0}\\\\\text{Molality of }MgCl_2=1.58m$

Hence, the molality of magnesium chloride is 1.58 m

5 0

3 years ago

Read 2 more answers

A student explained to the class that helium has 8 valence electrons because it is in group 18. Is the student correct?

lys-0071 [83]

The student is incorrect because helium has 2 valence electrons and it's in group 18 because the first energy level is full. Although helium is placed in Group 18 which generally has 8 valence electrons, it does not have 8 valence electrons as the student suggested. It was grouped together with the noble gases because it exhibits similar properties with them.

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3 years ago