1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tema [17]
3 years ago
14

A TLC plate showed 2 spots with Rf values of 0.25 and 0.26. The plate was removed from the developing chamber, the residual solv

ent was allowed to evaporate from the plate, and then the plate was returned to the developing chamber. What would you expect to see after the second development was complete
Chemistry
1 answer:
Katena32 [7]3 years ago
4 0

Answer:

See explanation

Explanation:

TLC is a chromatographic method in which the solute is spotted on a plate and the plate is placed in an air tight chamber containing a solvent. The solvent is maintained below the level of the spot. The capillary movement of the solvent through the plate achieves the required separation.

If two spots have Rf values of 0.25 and 0.26 respectively and then the plate was removed from the developing chamber, subsequently, the residual solvent was allowed to evaporate from the plate, and then the plate was returned to the developing chamber.

It will be observed after the second development is complete that the new Rf values will be 0.50 and 0.52 respectively. It will just be as though the second chromatogram picked up from where the first chromatogram stopped.

You might be interested in
Use the fact that to determine how much the pressure must change in order to lower the boiling point of water by a small amount
erma4kov [3.2K]

Complete Question

Use the fact that d\mu=\frac{V}{N}dp-\frac{s}{N}dT to determine how much the pressure must change in order to lower the boiling point of water by a small amount 3.20e-01 K. You may assume that the entropy and density of the liquid and gas are roughly constant for these small changes. You may also assume that the volume per molecule of liquid water is approximately zero compared to that of water vapor, and that water vapor is an ideal gas. Useful constants: Atmospheric pressure is 101300 Pa The boiling point of water at atmospheric pressure is 373.15 K The entropy difference between liquid and gas per kilogram is 6.05e 03 J/kgK The molecular weight of water is 0.018 kg/mol. (a) 0.00e 00 Pa (b) 1.14e 03 Pa (c) 6.85e 26 Pa (d) 4.24e 05 Pa (e) 3.81e 28 Pa

Answer:

Correct option is B

Explanation:

From the question we are told that:

Given Equation d\mu=\frac{V}{N}dp-\frac{s}{N}dT

Change of boiling point \triangle H=3.20e-01 K

Generally the equation for Change in time is mathematically given by

  d\mu=\frac{V}{N}dp-\frac{s}{N}dT

  dp=\frac{s}{v}dT

Where

    s=Entropy\ difference *molar\ weight

    s=6.05*10^3*0.018j/mol.k

And

    V=\frac{RT}{P} (from ideal gas equation)

Therefore

 dp=\frac{Ps}{RT}dT

 dp=\frac{101300*6.05*10^3*0.018}{8.314*373.15}3.20*10^{-1}

 dp=1137.873pa

 dp=1.14e 03 Pa

Therefore correct option is B

4 0
3 years ago
The specific heat capacity of a certain type of cooking oil is 1.75 J/(g⋅∘C). What is the amount of heat exchanged when the temp
anygoal [31]

Answer:

Q = -811440 J

Explanation:

Given data:

Mass of oil = 2.76 Kg (2.76× 1000 = 2760 g)

Initial temperature = 191 °C

Final temperature = 23°C

Specific heat capacity of oil = 1.75 J/g.°C

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 23°C - 191 °C

ΔT = -168°C

Q = 2760 g ×1.75 J/g.°C  ×-168°C

Q = -811440 J

Negative sign show heat is released.

6 0
3 years ago
Aluminum and oxygen react according to the following equation: 4Al(s) 3O2(g) --> 2Al2O3(s) What mass of Al2O3, in grams, can
algol [13]

Answer:

8.66 g of Al₂O₃ will be produced

Explanation:

4Al (s) + 3O₂ (g)  → 2Al₂O₃ (s)

This is the reaction.

Problem statement says, that the O₂ is in excess, so the limiting reactant is the Al. Let's determine the moles we used.

4.6 g / 26.98 g/mol = 0.170 moles

Ratio is 4:2.

4 moles of aluminum can produce 2 moles of Al₂O₃

0.170 moles of Al, may produce (0.170  .2)/ 4 = 0.085 moles

Let's convert the moles of Al₂O₃ to mass.

0.085 mol . 101.96 g/mol = 8.66 g

3 0
3 years ago
Read 2 more answers
What organelles are involved in the production of proteins
DanielleElmas [232]

Answer:

endoplasmic reticulum (ER)

7 0
3 years ago
Read 2 more answers
A measure of how closely individual measurements agree with one another 1 point<br> is
rewona [7]

Precision

Precision: A measure of how closely individual measurements agree with one another. Accuracy: Refers to how closely individual measurements agree with the correct or true value.

6 0
3 years ago
Other questions:
  • What is the Sun's life span?
    8·1 answer
  • Question: A boy swimming in a lake smacks the surface of the water with his hand, creating sound waves that travel through the w
    15·1 answer
  • How much time will you save on a ten mile trip if u travel at 60mph rather than at 55mph?
    9·2 answers
  • Which of the following alkyl halides has the smallest molecular dipole moment?
    10·1 answer
  • Which of the following demonstrates that reactants and products are chemically different? Choose all that apply
    11·2 answers
  • Why does adding lemon juice to a blueberry smoothie<br> make it change color from purple to pink.
    9·1 answer
  • A chemist mixed two substances together: a blue powder with no smell and a colorless liquid with a strong smell. Their repeating
    13·1 answer
  • How many grams calcium sulfite are in a 3.87 mole sample?
    6·1 answer
  • Identify if the equation below is redox or not 2KOH (aq) + H₂S04(aq) H₂SO4(aq)+H₂O​
    5·2 answers
  • Can a chemical reaction take place without enzyme​
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!