Answer:
See explanation
Explanation:
In TLC, the plate is spotted at a point above the solvent front and the solvent moves up the plate by capillary action leading to the separation of the various components of the mixture spotted on the plate.
However, if the TLC plate is allowed to remain in the developing chamber for too long such that the solvent front reaches the top of the plate, the components of the mixture will recombine at the top of the plate and cancel out any separation which may have occurred on the plate.
cuáles son las características de la luz y en qué consisten
Answer:
Cuáles son las características de la luz y en qué consisten?
Explanation:
La luz es una radiación que se propaga en forma de ondas. Las ondas que se pueden propagar en el vacío se llaman ONDAS ELECTROMAGNÉTICAS. La luz es una radiación electromagnética
A student carries out a flame test on an unknown solid. a red flame is seen. the student concludes that the solid is lithium carbonate. explain why this conclusion is not justified
(a) Calculate the pH of a buffer that is 0.12 M in lactic acid and 0.11 M in sodium lactate. (b) Calculate the pH of a buffer formed by mixing 85 mL of 0.13 M lactic acid with 95 mL of 0.15 M sodium lactate.
Answer:
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Draw the curved arrows showing a proton transfer reaction, and draw the products of that proton transfer. Do not include the Li counterion, and lone pairs are not required in the products.
Answer:
Draw the curved arrows showing a proton transfer reaction, and draw the products of that proton transfer. Do not include the Li counterion, and lone pairs are not required in the products and the question is hsown below:
Explanation:
The proton from water is abstracted by butyl carbanion and hydroxide ion is formed from water.
The reaction is shown below in the attachment.
Why must the spot applied to a TLC plate be above the level of the developing solvent? What problem will ensue if the level of the developing liquid is higher than the applied spot in a TLC analysis?
Answer:
See explanation
Explanation:
If the spot in TLC is below the solvent front, it will be observed that the spot, instead of being separated by the solvent as expected, will just dissolve away in the solvent and zero actual separation of the mixture is achieved.
If the solute is dissolved away instead of being separated by the solvent, then the experiment fails because no actual separation of the mixture is achieved.
Hence, in TLC, the spot must be applied above the solvent front so that the capillary movement of the solvent through the plate can lead to the eventual separation of the components of the mixture since the various components of the mixture will travel at different speeds through the plate.
Also, if the solvent is above the spot, the solvent may evaporate selectively from the points above the spot while separation is ongoing.
28) Which of the following is true about the modern model of the atom?
A) Electrons orbit the nucleus in shells at fixed distances
B) Protons, neutrons, and electrons are located in the nucleus.
C)Atoms are hard, indivisible spheres.
D)A positive nucleus is surrounded by negative electrons.
Answer:
A) Electrons orbit the nucleus in shells at fixed distances
Answer:
the answer is A
Explanation:
select the two atomic models that belong to the same element !
Answer:
The second and the third atomic model.
Explanation:
An element is identified by the no. of protons in the said element. Proton number cannot be changed. Both second and third atomic model have 5 protons, so they are of the same element.
An elephant walks north from a watering hole for 1 mile. The elephant
encounters a hill and turns east. The elephant continues to walk east until it
reaches a tree. It stays near the tree for 1 hour before continuing on to a
grassy field. Which point of reference should be used to describe the
elephant's motion?
A. The grassy area
B. The hill
STA
Tel
C. The tree
D. The watering hole
Answer:
i think its c because thats when the direction changes and you dont know where he went.
Explanation:
What term describes the process of lowering the boiling point of a hydrocarbon by exposing it to different environmental treatments such as hydrogen enriched catalysts or high temperatures
Answer:
Cracking.
Explanation:
A chemical reaction can be defined as a reaction in which two or more atoms of a chemical element react to form a chemical compound. An example of a chemical reaction involving hydrocarbons is cracking.
Hydrocarbon can be defined as an organic compound that comprises of hydrogen and carbon only.
In Organic chemistry, cracking refers to the process of lowering the boiling point of a heavy, complex or long-chain hydrocarbon such as kerogens by exposing it to different environmental treatments such as hydrogen enriched catalysts, pressure or high temperatures, in order to produce smaller, lighter and more useful molecules (alkanes and alkenes) such as gasoline, diesel fuel, etc.
Atoms are neutral because the number of
Answer:
electrons and protons
Explanation:
Literally search it up
(a) Describe the process by which Nitrogen is obtained from air on a large scale
The element nitrogen exists as a gas and is obtained from air on a large scale by fractional distillation of air.
What is an element?An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
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Why all mushrooms cannot be eaten?
Explanation:
The toxins present are secondary metabolites produced by the fungus. Mushroom poisoning is usually the result of ingestion of wild mushrooms after misidentification of a toxic mushroom as an edible species. ... The safety of eating wild mushrooms may depend on methods of preparation for cooking.
The specific heat capacity of liquid ethanol is 2.42 J/gºC.
How many joules of heat must be absorbed by 0.463 g ethanol to change its temperature from 51.6 °C to 82.4 °C?
Show work to receive credit.
Match the following parts of an atom to their description.
Neutron
?
Negatively charged
particle that moves
around the nucleus
Nucleus
?
Positively charged particle
in the nucleus
Electron
2
Noncharged particle in the
nucleus
Proton
?
Composed of protons and
neutrons
Answer:
Neutron - non charged particle in nucleus
nucleus - composed of proton and Neutron
electron - negatively charged particle that moves around the nucleus
proton - positively charged particle in the nucleus.
Explanation:
these the are definitions of the terms
12. NAD and NADPH are distinguished from each other by the
that's bonded to the sugar ring attached to the adenine.
O A. phosphate group
O B. adenine
O C. carbon dioxide
O D. nicotinamide
Answer:
A. phosphate group
Explanation:
I got it right in class!
Hope this Helps!! :))
How do scientists test their ideas
When Logan opens a new bottle of carbonated beverage, the sudden release of pressure causes the beverage to bubble up and overflow. What could Logan do in the future to prevent the next bottle from overflowing when he opens it
Answer:
When Logan opens a new bottle of carbonated beverage, the sudden release of pressure causes the beverage to bubble up and overflow. What could Logan do in the future to prevent the next bottle from overflowing when he opens it.
Explanation:
This is an application of Boyle's law.
According to Boyle's law:
the volume of a fixed amount of gas is inversely proportional to its pressure at a constant temperature.
[tex]V \alpha \frac{1}{P}[/tex]
So, if pressure reduces all of a sudden, the volume increases and this causes an overflow of the beverage from the bottle.
To avoid this situation, the pressure inside the bottle should not be released at once. The bottle cap should be opened slowly in such a way that opens a little and then close again open a little and then close like that many times if we do, then pressure inside the bottle goes slowly then, the volume will not increase all of a sudden.
In the reaction below, what is the limiting reactant when 1.24 moles NH3 of reacts with 1.79 moles of NO?
4NH_3 + 6NO (right arrow) 5N_2 + 6H_2O
1. NO
2. H_2O
3. NH_3
4. N_2
Answer:
Option 1. NO
Explanation:
The balanced equation for the reaction is given below below:
4NH₃ + 6NO —> 5N₂ + 6H₂O
From the balanced equation above,
4 moles of NH₃ reacted with 6 moles of NO.
Finally, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
4 moles of NH₃ reacted with 6 moles of NO.
Therefore, 1.24 moles of NH₃ will react with = (1.24 × 6)/4 = 1.86 moles of NO
From the calculation made above, we can see that a higher amount of NO (i.e 1.86 moles) than what was given (i.e 1.79 moles) is needed to react completely with 1.24 moles of NH₃.
Therefore, NO is the limiting reactant and NH₃ is the excess reactant.
Thus, the 1st option gives the correct answer to the question
Answer:
1. NO .
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to identify the limiting reactant by simply calculating the moles of any product, say N2, via the moles of each reactant and including the corresponding mole ratio (4:5 and 6:5):
[tex]1.24molNH_3*\frac{5molN_2}{4molNH_3}=1.55molN_2 \\\\1.79molNO*\frac{5molN_2}{6molNO}=1.50molN_2[/tex]
Thus, since NO yields the fewest moles of N2 product, we infer it is the limiting reactant.
Regards!
Disadvantages of modern periodic table?
Answer:
It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.
The atomic numbers of some elements such as Protonium were just guessed.
A substance with two oxygen atoms is combined with a substance with one oxygen atom to form one product. What is true of the product?
There will be no oxygen in the product. Some of the oxygen will evaporate into the air.
In the presence of excess iodide ions, the iodine formed by reaction of iodide with NBS will react further to form triiodide ions. What does the triiodide combine with to form the blue color of the endpoint
Answer:
Starch.
Explanation:
When the triiodide combine with starch, it forms dark blue colour. Amylose in starch is responsible for the occurrence of a deep blue color when the iodine is combine with the starch. The iodine molecule goes inside of the amylose coil which makes a linear triiodide ion complex that goes into the coil of the starch that leads to an intense blue-black color in the end so we can say that starch turns the colour into blue.
The compound sodium hydrogen sulfate is a strong electrolyte. Write the reaction when solid sodium hydrogen sulfate is put into water:
Answer:
NaHSO₄(s) --H₂O--> Na⁺(aq) + HSO₄⁻(aq)
Explanation:
Sodium hydrogen sulfate is a strong electrolyte, that is, when dissolved in water it completely dissociates into the cation sodium and the anion hydrogen sulfate. The corresponding chemical equation is:
NaHSO₄(s) --H₂O--> Na⁺(aq) + HSO₄⁻(aq)
f(x) = -x2+x+6
x
-2
a
-1
4
0
b
1
6
2
c с
do
11 11 11
Cross primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant.
20ml of water is mixed with 40gm of fine powder. Calculate the concentration of the solution obtained.
Answer:
[tex]\%m=66.7\%[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the concentration of the solution obtained, by knowing 20 mL of water are the same to 20 g and therefore the mass of the solution is 40g+20g=60g.
Next, we apply the following equation to obtain the required concentration:
[tex]\%m=\frac{40g}{60g} *100\%\\\\\%m=66.7\%[/tex]
Regards!
I need help please ASAP
Which scientist developed the first model of the atom that showed the structure of the inside of an atom
Answer:
Which scientist developed the first model of the atom that showed the structure of the inside of an atom
Ernest Rutherford
how many molecules are there in 75.0 grams of phosphorus trichloride plzz helpp
Answer:
Explanation:
55
When a metal cation forms an octahedral complex the ligands approach directly along the x, y, and z axes. The two d orbitals with lobes along the axes will experience a _____ repulsion than the three d orbitals with lobes between the axes. The d orbitals will be split into two groups; the higher energy group has _____ orbitals and the lower energy group has _____ orbitals.
Answer:
greater, two, three
Explanation:
Cations are positively charged ions. In an octahedral complex, the d orbitals undergo greater repulsion and split into 2 high, and 3, low energy groups.
What are octahedral complexes?An octahedral complex is a molecular geometry of a compound in which the six atoms are aligned in symmetry around the central metal atom.
The molecule has eight faces and hence is called octa. The two d orbitals present in the structure experience greater repulsive force compared to the three orbitals of d orbit.
Therefore, the d orbit of the molecule has two high-energy orbitals while having three lower energy molecules.
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Consider the reaction between an alcohol and tosyl chloride, followed by a nucleophile. Write the condensed formula of the expected main organic product.
CH3CH2CH2OH---------- 2.CI 1.TsCl,pyridine__________
Answer:
Consider the reaction between an alcohol and tosyl chloride, followed by a nucleophile. Write the condensed formula of the expected main organic product.
CH3CH2CH2OH---------- 2.CI 1.TsCl,pyridine__________
Explanation:
Given alcohol is propanol.
When it reacts with TsCl, the hydrogen in -OH group is replaced with tosyl group.
Pyridine is a weak base and it neutralizes the HCl (acid) formed during the reaction.
The reaction is shown below:
what flora eat? pliz tell me someone
Answer:
flora eat food
Explanation:
because that what every living thing eats to grow.
Answer:
sugar??
Explanation:
plants photosynthesise to make their own food (mainly glucose) to be transported around the plant