If you eluted a TLC of a compound using 60% hexanes / 40% ethyl acetate as the solvent and obtained an Rf value of 0.5. If you changed the solvent system to 30% hexanes / 70% ethyl acetate, how would the Rf value change

Answers

Answer 1

Answer:

The Rf value change will be  >  0.5

Explanation:

Given that Change in Solvent is proportional to change in polarity of solvent system

The change from solvent composition of 60/40  to 30/70 will cause an increase in the polarity of the system .

and Increase in Polarity = Increase in Rf value  because the compound will move to a higher distance


Related Questions

Adding more than one equivalent of HCl to pent-1-yne will lead to which product:______.
a. 1,2-dichloro-1-butene.
b. 1,1-dichloropentane.
c. 2,2-dichloropentane.
d. 2,2-dichlorobutane.

Answers

Answer:

c. 2,2-dichloropentane.

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to firstly draw the structure of the reactant, pent-1-yne:

[tex]CH\equiv C-CH_2-CH_2-CH_2[/tex]

Now, we infer the halogen is added to the carbon atom with the most carbon atoms next to it, in this case, carbon #2, in order to write the following product:

[tex]CH\equiv C-CH_2-CH_2-CH_2+2HCl\rightarrow CH_3- CCl_2-CH_2-CH_2-CH_2[/tex]

Whose name is 2,2-dichloropentane.

Regards!

Standard hydrogen electrode acts as both anode and cathode.Explain.​

Answers

Answer:

A Standard Hydrogen Electrode is an electrode that scientists use for reference on all half-cell potential reactions. The value of the standard electrode potential is zero, which forms the basis one needs to calculate cell potentials using different electrodes or different concentrations. It is important to have this common reference electrode, just as it is important for the International Bureau of Weights and Measures to keep a sealed piece of metal that is used to reference the S.I. Kilogram.

Answer:

The role of an electrode as cathode or anode depends on the nature and electrode potential of the other electrode with which it forms the complete electrochemical cell.

When a cell is to be made with zinc electrode and hydrogen electrode, the hydrogen electrode will behave as a cathode and the zinc electrode will behave as anode because zinc is present above hydrogen in the activity series. That is zinc is more electropositive than hydrogen.

If the cell is made with a copper electrode and hydrogen electrode, the hydrogen electrode will behave as anode and the copper electrode as a cathode. This is due to the fact that Cooper is present below hydrogen in the activity series. Copper is less electropositive than hydrogen.

Explanation:

Spell out the full name of the compound. ​

Answers

Answer:

it is propane

C3H8 it is propane

The Full name of the given compound is Propane.

What is Propane ?

Propane is a three-carbon alkane with the molecular formula C₃H₈.

It is a gas at standard temperature and pressure, but compressible to a transportable liquid.

In the figure given ;

Black balls represents Carbon atomsWhite balls represents Hydrogen atoms

In the given figure, there is single bond present between Carbon and Hydrogen. Hence, The Full name of the given compound is Propane.

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Which statement best describes what happens during a chemical reaction?
A. Reactants change into products.
B. Reactants change into new reactants.
C. Products change into reactants.
D. Products change into new products.

Answers

Answer:

A. Reactants change into products

Hydrogen fluoride will react with glass (silicon dioxide. S_iO_2) according to the equation below What mass of HF is required to react completely with 16 0 g of glass? (Molar masses; Si 28 09 g/mol F 19 00 g/mol H. 1.01 g/mol O, 16.00 g/mol]
4HF(g) + SiO_2(s) --> SiF_4(g) + 2H_2O(g)
A. 5.33 g
B. 21.3 g
C. 64.0 g
D. 80.0 g
E. 320 g

Answers

Answer:

21.3 g. Option B

Explanation:

The reaction is:

4HF(g) + SiO₂(s) → SiF₄(g) + 2H₂O(g)

We analysed it and it is correctly balanced.

4 moles of hydrogen fluoride react to 1 mol of silicon dioxide in order to produce 1 mol of silicon fluoride and 2 moles of water vapor.

We determine molar mass of each reactant:

HF → 1.01 g/mol + 19 g/mol = 20.01 g/mol

SiO₂ → 16 g/mol . 2 + 28.09 g/mol = 60.09 g/mol

We convert mass to moles: 16 g . 1 mol /60.09g = 0.266 moles of glass

Ratio is 1:4. 1 mol of glass react to 4 moles of HF

Our 0.266 moles may react to (0.266 . 4) / 1 = 1.07 moles of gas

We convert moles to mass: 1.07 mol . 20.01 g/mol = 21.3 g

P.1 is a variant of SARS-CoV2. This is the so-called "Brazil variant". It has the amino acid the substitution N501Y in the spike protein on the virus surface. In cellular fluids at ~pH 7 the wild type spike protein has a net negative charge. This substitution will make the spike protein

more negative

less hydrophobic

able to absorb move UV light

less negative

Answers

There are various variants of Cov id virus. The Brazilian variant P also known as Gamma variant is the third variant of the original SARS-CoV2.

The correct answer is more negative

This variant has raised concerns since it has ability to spread more quickly then previous variants and this is more negative variant.

It is assumed that Cov id variant Gamma and Delta has ability to absorb move UV light but this is not proved yet and research is underway.

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which of the followong would change the element represented in the electron module?
a. adding 1 proton
b. adding 1 electron
c. adding 1 neutron
d. removing the electron​

Answers

Answer:

removing the electron.

The term that would change the element represented in the electron module is removing the electron​. The correct option is d.

What are elements?

Chemical elements are the elements that are represented in the periodic table. There are 118 chemical elements discovered and represented in the periodic table. There are many more to be discovered.

The model is of an element. Elements are made up of atoms, and atoms contain charged particles. Out of these particles, electrons are revolved around the nucleus, which determined the atomic number of the element, and different elements have different numbers of electrons.

Removing the electron from the element, will change the element or change its atomic number.

Thus, the correct option is d. removing the electron​.

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Use the periodic table, to determine which element the following spin diagram represents

Answers

The answer is A chlorine

ASSINGMENT Propane react with oxygen gas to form Carbondioxide and water a. If 2.8 mole of propone react with excess oxygen ges. how many grams of Carbondioxide will be form?​

Answers

Answer:

Propane (C3H8) reacts with Oxygen gas to form Carbon Dioxide and water.

a. If 2.8 moles of Propane reacts with excess Oxygen gas how many grams of CO2 will be formed?

b. How many grams of Oxygen gas will completely react with 3.8 moles of Propane?

c. If 25 g of C3H8 reacts with excess Oxygen, how many moles of water will be formed?

d. If 38 g of water are produced in the reaction, how many moles of CO2 were produced?

convert 36.52 mg to ?___ g

Answers

Answer:

0.0365 is your answer

Explanation:

hope it will help u

Answer:

365.2gㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ

Which one of these four atoms has the most neutrons?
O A.
79
Se
34
B.
80
Br
35
OC.
73
Ge
32
84
Kr
36
O D.

Answers

Answer:

kr

Explanation:

it is radioactive so it loss electron due to which it jas most neutons

Izopropanole doesn't form by Select one:
a. Reduction of propan-2-one
b. Hydration of 2-chloropropane
c. Hydration of propene
d. Reduction of propanal​

Answers

Izopropanol doesn't form by Hydration of propene.

What is Reduction of propan-2-one?

Acetone, propanone, or dimethyl ketone, exists as an organic compound with the formula (CH₃)₂CO. It stands for the simplest and smallest ketone. Reduction of ketones can be accomplished by hydrogenation (or) utilizing Grignard Reagent. Let us now decrease propanone to propan-2-ol by hydrogenation. The reduction of propane in the existence of catalyst platinum along with hydrogen provides the product propan-2-ol.

The correct answer is option A.

Izopropanol doesn't form by Hydration of propene.

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The electronic arrangement of an atom shows how electrons are distributed across the different energy levels. Which of the following elements is represented by the electron arrangement 2, 8, 18, 6?
А Сa
B. Mg
C. S
D Se
E. Ga

Answers

Answer:

The answer is D which is Selenium

What mass of NaNO3 must be dissolved to make 838mL of a 1.25 M solution

Answers

Answer:

89.04 g of NaNO₃.

Explanation:

We'll begin by converting 838 mL to L. This can be obtained as follow:

1000 mL = 1 L

Therefore,

838 mL = 838 mL × 1 L / 1000 mL

838 mL = 0.838 L

Next, we shall determine the number of mole of NaNO₃ in the solution. This can be obtained as follow:

Volume = 0.838 L

Molarity = 1.25 M

Mole of NaNO₃ =?

Mole = Molarity × volume

Mole of NaNO₃ = 1.25 × 0.838

Mole of NaNO₃ = 1.0475 mole

Finally, we shall determine the mass of NaNO₃ needed to prepare the solution. This can be obtained as follow:

Mole of NaNO₃ = 1.0475 mole

Molar mass of NaNO₃ = 23 + 14 + (16×3)

= 23 + 14 + 48

= 85 g/mol

Mass of NaNO₃ =?

Mass = mole × molar mass

Mass of NaNO₃ = 1.0475 × 85

Mass of NaNO₃ = 89.04 g

Therefore, 89.04 g of NaNO₃ is needed to prepare the solution.

A sample of Kr gas is observed to effuse through a pourous barrier in 8.15 minutes. Under the same conditions, the same number of moles of an unknown gas requires 4.53 minutes to effuse through the same barrier. The molar mass of the unknown gas is ____________ g/mol.

Answers

Answer:

25.88 g/mol

Explanation:

Graham's law is a famous law which states that the diffusion rate or the effusion rate of any gas varies inversely to the square root of the molecular weight the gas.

So from Graham's law, we have,

[tex]$\frac{\text{time}}{M^{1/2}}=\text{constant}$[/tex]

Using the sample of Kr gas having M = 83.8

[tex]$\frac{8.15}{(83.8)^{0.5}}= \frac{4.53}{M^{0.5}}$[/tex]

[tex]$M^{0.5}= 5.088$[/tex]

M = 25.88 g/mol

A 13.4 mL sample of CO2 gas was collected in an experiment.
What is this volume in liters (L)? Use significant figures, do NOT include the units.

Answers

Explanation:

here's the answer to your question

how many electrons does tin have?
A. 50
B. 68
C. 118​

Answers

how many electrons does tin have?

Answer : 2, 8, 18, 18, 4

Therefore, total electrons = 50

A.50
2,8,18,18,4
This is the right answer

If 50.0 g of sulfuric acid and 40.0 grams of barium chloride are mixed, how many grams of sulfuric acid and how many grams of barium chloride remain after the double replacement reaction is complete?

Answers

After the double replacement reaction is complete 0 grams of BaCl₂ and 31.16 grams of H₂SO₄ will remain.

First, we will write the balanced equation for the reaction

H₂SO₄ + BaCl₂  → BaSO₄ + 2HCl

This means 1 mole of BaCl₂ is needed to react completely with 1 mole of H₂SO₄ to give 1 mole of BaSO₄ and 2 moles of HCl

From the question, 50.0g of sulfuric acid is mixed with 40.0 grams of barium chloride. To determine the quantity of each substance remaining after the complete reaction, we will first determine the number of moles present in each of the reactant.

For H₂SO₄

mass = 50.0g

Molar mass = 98.079 g/mol

From the formula

Number of moles = Mass / Molar mass

∴ Number of moles of H₂SO₄ = 50.0g / 98.079 g/mol

Number of moles of H₂SO₄ = 0.5098 mol

For BaCl₂

mass = 40.0 g

Molar mass = 208.23 g/mol

∴ Number of moles of BaCl₂ = 40.0g / 208.23 g/mol

Number of moles of BaCl₂ = 0.1921 mol

Since the number of moles of H₂SO₄ is more than that of BaCl₂, then H₂SO₄ is the excess reagent and BaCl₂ is the limiting reagent (that is, it will be used up completely during the reaction)

From the equation, 1 mole of H₂SO₄ is needed to completely react with 1 mole of BaCl₂

∴ 0.1921 mol of H₂SO₄ will be needed to completely react with 0.1921 mol of BaCl₂.

Therefore, after the reaction is complete, 0 mole (i.e 0 grams) of BaCl₂ will remain and (0.5098 mole - 0.1921 mole) of H₂SO₄ will remain.

Number of moles H₂SO₄ that will remain = 0.5098 mole - 0.1921 mole = 0.3177 moles

Now, we will convert this to grams

From the formula

Mass = Number of moles × Molar mass

Mass of H₂SO₄ that will remain = 0.3177 moles × 98.079 g/mol

Mass of H₂SO₄ that will remain = 31.1597 g

Mass of H₂SO₄ that will remain31.16 g

Hence, after the double replacement reaction is complete 0 grams of BaCl₂ and 31.16 grams of H₂SO₄ will remain.

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What is Avogadro's number?
O A. 6.02 x 10-23
O B. 6.0223
C. 6.02 x 10
D. 6.02 x 1023

Answers

Answer:

E.6.02 10-23

Explanation:

Answer:

6.02×10^23 I hope it helps you

Explanation:

I hope it helps you

A substance is made up of slow-moving particles that have very little space between them. Based on this information, what can most likely be concluded about this substance? O It is not a gas because its particles do not move continuously. It is a gas because its particles move continuously in a straight line. 0 It is not a gas because its particles do not have large spaces between them. It is a gas because its particles move in many different directions.​

Answers

Answer:

o

Explanation:

it is not a gas because the particles do not move freely it may be a liquid or a solid partly and mostly liquidized.

Below is the structure of what should be the peptide Thr-Glu-Arg-Met. However, one of these residues has been drawn incorrectly. Identify this residue
Thr

Glu

Arg

Met

Answers

Answer:

the answer is glu and I know

The residue that has been drawn incorrectly is option (B) i.e. glu .

What is glutamate residue?

Glutathione consists of a glutamate residue linked to cysteine via its γ-carboxyl rather than the α-carboxyl group and followed by a conventional peptide bond between cysteine and glycine.

It plays an important role in maintaining the proper ratio of oxidized to reduced forms of metabolically important thiols such as coenzyme A.

It also provides reducing equivalents that detoxify reactive oxygen species such as peroxides.

The tripeptide is  regenerated through the concerted action enzymes in the so-called γ-glutamyl cycle.

The residue that has been drawn incorrectly is glutamate residue ,hence option (B) is correct.

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Which of the following have only a -C-O-C- functional group?

Answers

Answer:

B) ethers

Explanation:

The functional group of an organic compound defines its specificity. The functional group is responsible for the chemical behavior of an organic compound. For example, alkenes are known to have a carbon-carbon double bond (C=C) functional group.

Likewise, organic compounds known as ETHERS are known to possess an ethoxy functional group i.e. oxygen atom bonded to two alkyl groups (R- OR; where R is an alkyl group). Members of ether functional group includes dimethyl ether (CH3-O-CH3), diethyl ether (C2H5-O-C2H5).

Given its formula and Avogadro's Number (6.02 x 10^23 molecules/mol), deduce how many molecules are present in 3 x 10^-16 grams of TCDD. Type in only a number without using scientific notation.

Answers

Answer:

5 × 10⁵ molecules (500,000 molecules)

Explanation:

Step 1: Convert 3 × 10⁻¹⁶ g to moles

We will use the molar mass of TCDD (321.97 g/mol).

3 × 10⁻¹⁶ g × 1 mol/321.97 g = 9 × 10⁻¹⁹ mol

Step 2: Convert 9 × 10⁻¹⁹ mol to molecules

The required conversion factor is Avogadro's number (6.02 × 10²³ molecules/mol).

9 × 10⁻¹⁹ mol × 6.02 × 10²³ molecules/1 mol = 5 × 10⁵ molecules

How many neutrons does Carbon- 14 and Carbon -15 have? *

Answers

Answer: 8 for both

Explanation:

The standard free energy that is required for the sodium-potassium ATPase to pump two K ions into the cell and three Na ions is 43.8 kJ/mol but the standard free energy change of hydrolysis of ATP is only -32 kJ/mol. This apparent imbalance of free energy can be accounted for because ________.

Answers

Answer:

Explanation:

This apparent disparity of the free energy can be taken into account because:

the free energy produced by the hydrolysis of one ATP is adequate enough under psychological circumstances.

The Na-K ATPase aids the pumping of Na+ ions out of the cell and K+ ions into the cell. These actions occurring against their potential(concentration) gradients, which may be produced by hydrolyzing one ATP molecule.

How many grams of Br are in 445 g CaBr2 ?

Answers

Answer:

156 g Br. Explanation: In order to figure out how many grams of bromine you get in that many grams of calcium bromide, CaBr2 , you must find ...

Answer:

156 g

Explanation:156 g

plss muje brilliant bana lo plss

The element of the electron configuration is sodium. If it were to come near a fluorine atom, the sodium atom would give away its only valance electron to the fluorine atom have. That would make the sodium atom become positively charged and the fluorine atom become negatively charged.

Answers

Answer:

The answer is attached below

Explanation:

The answer is the photo attached

The Nernst equation at 20oC is:
Eion= 58 millvolts/z. [log10 (ion)out/(ion)in]

Calculate the equilibrium potential for Cl- if the concentration of Cl- outside of the cell is 100 and the concentration inside of the cell is 10 mmol/liter.

a. 58 millivolts
b. +58 millivolts
c. -116 millivolts
d. 0

Answers

Answer:

a. -58 millivolts

Explanation:

The given Nernst equation is:

[tex]E_{ion} = 58 millivolts /z \Big[ log_{10} \Big( \dfrac{[ion]_{out}}{[ion]_{in}}\Big) \Big]}[/tex]

The equilibrium potential given by the Nernst equation can be determined by using the formula:

[tex]E_{Cl^-} = \dfrac{2.303*R*T}{ZF} \times log \dfrac{[Cl^-]_{out}} {[Cl^-]_{in}}[/tex]

where:

gas constant(R) = 8.314 J/K/mol

Temperature (T) = (20+273)K

= 298K

Faraday constant F = 96485 C/mol

Number of electron on Cl = -1

[tex]E_{Cl^-} = \dfrac{2.303*8.314*298} {(-1)*(96845)} \times log \dfrac{100} {10}[/tex]

[tex]E_{Cl^-} = - 0.05814 \ volts[/tex]

[tex]\mathsf{E_{Cl^-} = - 0.05814 \times 1000 \ milli volts}[/tex]

[tex]\mathsf{E_{Cl^-} \simeq - 58\ milli volts}[/tex]

Why must oxidation be accompanied by a reduction?
A. The species being oxidized shares electron(s) with the species that is reduced
B. The species being oxidized takes electron(s) from some other
C. Electrons can be given up to free space. species being oxidized must transfer electron(s) to some othen
D. Electrons cannot just be given up to free space.

Answers

Answer:

A

Explanation:

because the species being oxidized shares electrons with the species that is reduced.making the oxidized element positively charged and the reduced element negatively charged.

I hope this helps

Alphabet:B. the species being oxidized takes electron from some other

The reversible reaction 2H2 CO <------> CH3OH heat is carried out by mixing carbon monoxide and hydrogen gases is a closed vessel under high pressure with a suitable catalyst . After equilibrium is established at high temperature and pressure, all three substances are present. If the pressure on the system is lower, with the temperature kept constant, what will be the result

Answers

Answer:

The amount of CH3OH present in the mixture would decrease

Explanation:

According to Le Cha-telier's principle, when a reaction is in equilibrium and one of the constraints that influence the rate of reactions is applied, the equilibrium would shift so as to neutralize the effects of the constraint.

In this case, looking at the equation of the reaction:

2H2 + CO <------> CH3OH + heat

the total number of moles on the reactant's (left hand) side is 3 (2+1) while on the product's (right hand) side, it is 1. If the pressure on the system is increased, more CH3OH (and less of H2 and CO) will be produced because its side has the lower number of moles out of the two sides.

If the pressure on the system is otherwise lowered, more of H2 and CO would be produced while the amount of CH3OH present would gradually decrease.

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