If the TLC plate are left in the chamber for too long after the solvent reached the top the [tex]R_{f}[/tex] value achieved from experimentation will be different than the expected [tex]R_{f}[/tex] .
What is [tex]R_{f}[/tex] value?The value [tex]R_{f}[/tex] is the ratio of the distance traveled by the solute to the distance traveled by the solvent. The term comes from chromatography when it was discovered that a particular component in a particular solvent always migrates the same distance under the same conditions.
In chromatography, the value of [tex]R_{f}[/tex] is the basic requirement of the experiment. It indicates whether the analyte (solute) prefers the stationary or mobile phase. For stationary and mobile phases, the [tex]R_{f}[/tex] value is used to determine polarity, relative mass, relative solubility, etc.
If the TLC plate is left in the development chamber for too long, solvent will flow to the top of the plate, causing unexpected migration of the chemicals coated on the silica plate. So the experimentally obtained value [tex]R_{f}[/tex] is different from the expected value
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suppose that an atom has (i) 4, (ii) 5, electrons in different orbitals. what are the possible values of the total spin quantum number s? what is the multiplicity in each case?
The spin quantum number will be 2 and 2.5 and multiplicity in each case will be 5 and 6.
The angular momentum of such an electron is described by its spin quantum number (ms). An electron carries orbital angular momentum in addition to angular momentum around its axis of rotation. The Spin Quantum Number (s) really does have a magnitude (1/2) and a direction (+ or -) since angular momentum would be a vector.
(i) If an atom has 4 electrons then it will have total
Total spin quantum number = 1/2+1/2+1/2+1/2 = 4/2=2
Multiplicity = 2S+1= 2×2+1=5
(ii) If an atom has 5 electrons then it will have
Total spin quantum number = 1/2+1/2+1/2+1/2+1/2 = 5/2 = 2.5
Multiplicity = 2S+1= 2×2.5+1=6
Therefore, the spin quantum number will be 2 and 2.5
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what salt water body does the water you use in your home travel to?
Other natural therapies, such as salt water, can help soothe a sore throat. Gargling with salt water works well to destroy bacteria, reduce discomfort, and loosen mucus.
What does "remedying a situation" mean?When you fix something that is broken or harmful, you enhance it. To correct the situation, a lot has been done inside. Synonyms include rectify, redress, and reform. More remedies' opposites.
Describe the four treatments.The four primary categories of judicial remedies are (1) damages, (2) restitution, (3) coercive remedies, and (4) declaratory remedies. These categories are organized according to their intended use. Damages are typically used as a remedy to make up for any harm that has been done to the affected party.
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what is the abbreviated nomenclature for a 14-carbon omega-3 fatty acid that contains no other double bonds?
14:1 (delta 11) denotes the presence of a single double bond at carbon 11, starting at the carboxyl terminus, in the fatty acid.
How is omega-3 created?
The chloroplasts of plants, including grass, leaves, green algae, and other plants, produce omega-3s. Fish, animals, and humans are unable to make omega-3s on their own. Instead, they obtain them from this vegetation.
Explanation:
With the exception of steroids, fatty acids are carboxylic acids that provide the structural foundation of fats, oils, and all other types of lipids. More than 70 have been found in the natural world. They are typically unbranched, have an even number of carbon atoms, and can be divided into groups based on the existence and quantity of carbon-to-carbon double bonds.
14:1 (delta 11) denotes the presence of a single double bond at carbon 11, starting at the carboxyl terminus, in the fatty acid.
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The ratio :14 (delta 11) inside the fatty acid indicates a lone double bond at carbon 11, starting at the 3'-end.
How is omega-3 created?In their chloroplasts, plants such as grasses, leaves, cyanobacteria, and other flora all produce omega-3 fatty acids. Fish, animals, or humans cannot create omega-3s on their own. Instead, they get them from this facility.
Explanation:Fatty acids, which are naturally acidic, are the components of oils, oils, and other lipids as well as the legos of steroids. The natural world has more than 70 that have been discovered. They can be classified into categories based on the number and amount of coal single bonds, and are often spindle-shaped.
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at 1 atm pressure the heat of sublimation of gallium is 277 kj/mol and the heat of vaporization is 271 kj/mol. how much heat is required to melt 0.500 mol of gallium at 1.00 atm pressure?
At 1 atm pressure the heat of sublimation of gallium is 277 kJ/mol and the heat of vaporization is 271 kJ/mol. heat is required to melt 0.500 mol of gallium at 1.00 atm pressure is 3 kJ.
The data given as follows :
The heat of sublimation of gallium = 277 kJ/mol
The heat of vaporization = 271 kJ/mol
The difference between the heat of sublimation of gallium and the heat of vaporization is given as :
ΔH = heat of sublimation - heat of vaporization
ΔH = 277 kJ/mol - 271 kJ/mol
ΔH = 6 kJ/mol
The heat required = n ΔH
= 0.500 × 6
= 3 kJ
Thus, At 1 atm pressure the heat of sublimation of gallium is 277 kJ/mol and the heat of vaporization is 271 kJ/mol. heat is required to melt 0.500 mol of gallium at 1.00 atm pressure is 3 kJ.
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what is the rate constant for the reaction? express your answer in liters per mole per minute to two significant figures.
The rate constant for the reaction is the relation between the concentration of the reactant and the chemical rate of reaction.
The rate constant of the chemical reaction is the proportionality constant that describes the relationship between the concentration of the reactants and the chemical rate of reaction. The symbol of rate constant is k. Rate is depends on the temperature. unit for the zero order reaction is : L⁻¹ s⁻¹. unit of rate constant for the first order reaction is : s⁻¹. unit for the rate constant for second order reaction is : mol⁻¹ L s⁻¹.
Thus, The rate constant for the reaction is the relation between the concentration of the reaction and the chemical rate of reaction.
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why does recovered singal have 3 or 4 volatge level instead of 2 levels as you would excpect for a digtal signal
The digital signal is a signal that encodes data as a series of discrete values; at any one moment, it can only take on a maximum of one of a finite set of values.
A digital signal, in contrast, represents continuous values; it always reflects a real number within a continuous range of values. Information is represented by simple digital signals in discrete analogue level bands. The same information state is represented by all levels in a band of values. The signal in the majority of digital circuits can have two legitimate possible values; this is known as a binary signal or logic signal.
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1. What might cause cosmic radiation to be deflected around Earth?
after performing a tlc experiment, a researcher determines the rf value of a component to be 2. he also notes that the solvent travelled a distance of 4cm on the plate. what can you conclude about this experiment?
The conclusion would be that Rf value is wrong.
Rf value refers to the retention factor. It is used in Thin Layer Chromatography, which is the technique to identify molecules based on their polarity. The. rf value is the ratio of distance travelled by solute to the distance travelled by solvent.
Solute can not move faster than solvent, hence, the distance travelled is always less. This means that numerator will be less than denominator making it less than 1. In general, the rf value lies between 0 and 1. Therefore, there is something wrong in the experiment.
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calculate the ph for each case in the titration of 50.0 ml of 0.160 m hclo(aq) with 0.160 m koh(aq). use the ionization constant for hclo. what is the ph before addition of any koh? what is the ph after addition of 25.0 ml koh?
pH before addition of any KOH = 4.10
pH after addition of any KOH = 7.40
What is pH?The quantitative measure of the acidity or basicity of aqueous or other liquid solutions is known as pH. In pure neutral (neither acidic nor alkaline) water, the concentration of hydrogen ions is 10⁻⁷ gram-equivalents per liter, which means a pH of 7. Solutions below pH 7 are acidic. Solutions of pH greater than 7 are basic or alkaline.
For the given question:
HClO ⇄ H⁺ + ClO⁻
Kₐ = 4 × 10⁻⁸
Kₐ = [H⁺ ][ClO⁻]/[HClO]
Let, [H⁺ ] = [ClO⁻] = x
Since [HClO] = 0.160 M
Then,
4 × 10⁻⁸ = x²/0.160
x = 8.0 × 10⁻⁵ M which is [H⁺ ]
pH = -log[H⁺ ]
pH = 4.10
Now initial moles of HClO = 0.05L × 0.160 mol/L
= 8 × 10⁻³ mol
Addition of 25.0 ml KOH adds 4 × 10⁻³ mol of KOH which reacts with HCl forming 4 × 10⁻³ mol ClO⁻ leaving 4 × 10⁻³ mol of HClO
Concentration [ClO⁻] = 4 × 10⁻³ mol / 0.0750L
= 0.0533M
Now,
Kₓ = 4 × 10⁻⁸
= [H⁺ ](0.0533)/(0.0533)
[H⁺ ] = 4 × 10⁻⁸
pH = 7.40
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I am working on a Bohr Rutherford Diagram for Science right now, and my first question on the textbook is "draw a Bhor Rutherford Diagram for Sulfur-32."
How do I figure out how many dots I put in the Diagram?
The number of dots in the Bohr Rutherford Diagram for sulphur-32 is equal to 16 as the dots represent the number of electrons and the sulfur atoms have 16 in its atom. Bohr Rutherford's Diagram of sulphur-32 is shown below.
What is Bohrs' model of an atom?Bohr's model described the atomic structure by explaining the electrons move in definite and fixed orbitals or electron shells. Boh's model proposed that atoms contain a nucleus and the electrons surround this atomic nucleus.
Each orbit has fixed energy and the energy levels are represented with integer 1, 2, 3,.... and sometimes also represented as K, L, M, N...... shells.
When the electron moves from a lower energy level to a higher energy level then it absorbs energy and when the electron falls from a higher energy level to a lower energy level then it emits energy.
The atomic number of the sulfur atom is 16 so it has 16 electrons. Therefore, we can show 16 dots surrounding the nucleus in the Bohr-Rutherford Diagram.
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how many grams of h2so4 must be dissolved in 1.08 l of solution to generate a solution with a concentration of 2.69 m
The mass of H₂SO₄ that must dissolved in 1.08 liters of solution to make 2.69M solution is 271.52 grams.
The molarity of the substance is defined as the number of moles of solute per unit volume of solution in liters.
In this case,
The volume of the solution is 1.08 L.
The required molarity of the substance is 2.69M.
So,
we can write,
Molarity = Moles/Volume
Moles = Molariyt x volume
Moles =2.69 x 1.03
Moles = 2.77
Moles = Mass required/molar mass.
Molar mass of H₂SO₄ is 98 g/mol.
Putting values,
2.77=Mass required/98
Mass required = 271.52 grams.
So, 271.52 grams of H₂SO₄ is required to make 2.69M solution.
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which of the following are examples of relative dating methods? select one: a. all of the above. b. dendrochronology and seriation. c. seriation and fluorine, uranium, nitrogen dating. d. dendrochronology and the law of superposition.
Dendrochronology and seriation give the idea of the past events around us. Therefore, option B is the correct answer.
Dendrochronology is both an old and a modern science. Just counting tree rings sounds simple, but in the context of forest dynamics tree age is an important and valuable parameter.
Calculating the years of the formation of tree gives us the idea of how old and strong that particular tree is. It is important in case of geology.
For a long time, dendrochronology was associated with the dating of old houses, paintings, and archaeological samples. In recent decades however it has become a science with a broad range of applications such as global climate change, canopy process decline, the carbon cycle, and many others.
Seriation, also called artifact sequencing, is an early scientific method of relative dating, invented by the Egyptologist Sir William Flinders Petrie in the late 19th century
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How many ml of a 14.0 m nh3 stock solution are needed to prepare 200 ml of a 4.20 m dilute nh3 solution?
60 ml of a 14.0 M NH₃ stock solution are needed to prepare 200 mL of a 4.20 M dilute NH₃ solution.
Using the formula given below ,
M₁ x V₁ = M₂ x V₂
M₁ = concentration of stock solution
V₁ = volume of stock solution (to be found out)
M₂ = concentration of diluted solution
V₂ = volume of diluted solution;
V₁ = (M₂ x V₂) / M₁
= (4.2 x 200) / 14
= 60ml
Hence , 60 ml of a 14.0 Mole NH₃ stock solution are needed to prepare 200 mL of a 4.20 M dilute NH₃ solution.
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What is like the mitochondria?
O Excretory system
Digestive system
O Nervous system
O Skeletal System
Answer:
digestive system
.
Explanation:
100. grams of ammonia (nh3) is dissolved in a 8.3 l solution. what is the molarity of the resulting solution? report your answer with the correct number of significant figures.
The molarity of a resulting solution is 0.707 mol/L
The molarity of a solution is defined by the amount of solute in moles divided by the volumes of solution in litres.
1 grams of ammonia is equals to 0.05872 mol
100 grams of ammonia is equals to 5.872 mol
Molarity of a resulting solution would be = 100 gm of NH3 / 8.3 L of a solution.
That is 5.872 moles of NH3 / 8.3 of a solution.
Molarity of a resulting solution would be 0.707 mol/L of a solution.
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22) in the polysaccharide amylose, large numbers of monosaccharides are linked together through . a) alpha 1-4 glycosidic linkages b) beta 1-4 glycosidic linkages c) alpha 1-6 glycosidic linkages d) beta 1-6 glycosidic linkages e) none of the above
In the polysaccharide amylose,a large number of monosaccharides are linked together through alpha 1-4 glycosidic linkages.
Alpha 1-4 linkage is a stored form of sugar in plant. In this carbon atom 1 and 4 of the the two monomers forms a glycosidic bond. Polysaccharides are long chain forms of monosaccharides linked together by glycosidic bonds.A glycosidic bond is a covalent bond that joins a carbohydrate molecule to another group.this bond gives glycogen that is suitable for energy storage.
Amylose is plant starch made from monosaccharide connected through alpha 1-4 linkages.monosaccharides are the simplest form of sugar.from monosaccharides, all carbohydrates are built.
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How can science help places that are affected by natural disasters?
Answer:
The answer is sophisticated earthquake early-warning systems, increasingly accurate storm forecasting, and innovative flood risk and flood mitigation projects provide communities with the tools they need to respond to impending hazard events, and infrastructure design and engineering improvements help to reduce the damage suffered
Explanation:
I hope this helps
the kb for a weak base is 1.00 x 10-9. what is the % ionization of a 2.00 m aqueous solution of the base?
The % ionization of a 2.00 m aqueous solution of the base is 0.0022%
What is pOH ?
It is a measure of the hydroxide ion (OH-) concentration of a solution. Therefore, it can be used as an indicator of the alkalinity of a substance and, in some cases, also as an indicator of electrical conductivity. pOH is the negative logarithm of hydroxide ion content and is given by the formula:
pOH = 14 - pH
OH = Kw /OH+
where Kw = self-ionization content of water.
Applying the logarithm on both sides, the more general form of the equation is: In relation to corrosion, pOH can be used as an indicator of electrolyte conductivity in galvanic cells. The conductivity of a solution depends on the concentration of ions that act as charge carriers. The higher the concentration of OH ions, the stronger the alkalinity, the higher the conductivity of the electrolyte, and the higher the rate of galvanic corrosion.
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which of the following is true about free radicals? a. they are unstable and highly reactive molecules. b. they act as antioxidants in the body. c. they defend against cancer.
It is true about free radicals. a. they are unstable and highly reactive molecules.
Hydrogen peroxide and hydroxyl ions are two examples of oxygen-containing molecules with an unbalanced number of electrons. The unequal distribution of electrons makes it simple for them to interact with other molecules. To combat free radicals, use antioxidants. Heart disease and cancer are caused by free radicals. an unstable molecule type produced by typical cell metabolism The physiological metabolism produces some of these reactive molecule species (RMS), also known as "Hydrogen peroxide and hydroxyl ions are two examples of oxygen-containing molecules with an unbalanced number of electrons. The unequal distribution of electrons makes it simple for them to interact with other molecules. To combat free radicals, use antioxidants. Heart disease and cancer are caused by free radicals. an unstable molecule type produced by typical cell metabolism The physiological metabolism produces some of these reactive molecules species (RMS), also known as "free radicals" or "oxidants." Cell compartments and cells are hurt or destroyed when RMS concentrations go above a certain free radicals" or "oxidants." Cell compartments and cells are hurt or destroyed when RMS concentrations go above a certain point. These reactive molecules species (RMS), also known as "free radicals" or "oxidants," are a by-product of some physiological processes.
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in the next three problems, we will attempt to solve the problem: what is the standard entropy change for the combustion of 1 mole of diamond at room temperature?
The standard entropy change for the combustion of 1 mole of diamond at room temperature is 6.22 J / K mol.
The reaction is given as :
C (diamond) + O₂ -----> CO₂
At room temperature the value of S° is given as follows :
C = 2.38 J / K mol
O₂ = 205.2 J/Kmol
CO₂ = 213.8 J/Kmol
The standard entropy change is given as :
ΔS° = ∑S° product - ∑ S° reactant
ΔS° = ( 213.8 ) - ( 2.38 + 205.2)
ΔS° = 213.8 - 207.58
ΔS° = 6.22 J / K mol
Thus, The standard entropy change for the combustion of 1 mole of diamond at room temperature is 6.22 J / K mol.
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Question 8(Multiple Choice Worth 4 points)
(01.04 LC)
What best describes a material's ability to dissolve?
O Solubility
O Melting point
O Boiling point
O Thermal conductivity
Answer:
Solubility is the best to dissolve
Neurons that are rare, small, and lack features that distinguish dendrites from axons are called.
Answer:Anaxonic Neurons
Explanation:
What mass of iodine is produced when 14.2 grams of chlorine reacts with potassium iodine?
Answer:
50.8g of iodine is produced.
Explanation:
You have to do stoichiometry. To get grams of iodine produced.
Start with grams of chlorine that you're givenConvert these to moles (using molar mass)Convert moles of Cl2 into moles of I2Convert moles of I2 into grams of I2 (using molar mass)(Remember to multiply across the top and divide by the bottom)
[tex]\frac{14.2g Cl2}{1} * \frac{1 mol Cl2}{70.9g} * \frac{1 mol I2}{1mol I2} * \frac{253.8g}{1 mol I2}[/tex]
find the volume of 0.250 m sulfuric acid necessary to react completely with 74.3 g sodium hydroxide.
The volume of 0.250 m sulfuric acid necessary to react completely with 74.3 g sodium hydroxide is 3.7 L.
The chemical reaction of sulfuric acid and sodium hydroxide is given as below:
H2SO4 + 2NaOH ------- Na2SO4 + 2H2O
From above, we noticed that, one mole of sulfuric acid react with two moles of sulfuric acid.
Therefore, firstly we convert grams of sulfuric acid into moles.
As we know that, molar mass of sodium hydroxide is 40 g.
What is mole?It is defined as the given mass to the molar mass of substance.
Mathematically,
Moles = Given mass / molar mass
Given mass of sulfuric acid = 74.3 g
By substituting all the values, we get
Moles = 74.3 / 40
= 1.85 mol
So, 1/2 moles of sulfuric acid one moles of sodium hydroxide.
Or, 1.85 moles of sodium hydroxide react with 1/2 × (1.85) moles of sulfuric acid.
1.85 moles of sodium hydroxide react with 0.925 moles of sulfuric acid.
Now,
Concentration of sulfuric acid = 0.250 M
Moles of sulfuric acid = 0.925 mol
C = m/ V
V = m/ C
= 0.925/ 0.250 = 3.7 L
Thus, we concluded that the volume of 0.250 m sulfuric acid necessary to react completely with 74.3 g sodium hydroxide is 3.7 L.
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Write the balanced neutralization reaction that occurs between h2so4 and koh in aqueous solution. Phases are optional.
The equilibrium equation for the neutralization reaction between H2SO4 and KOH in aqueous solution is
[tex]H_2SO_4 + 2KOH= > K_2SO_4 +H_2O[/tex]
Neutralization is a chemical reaction in which acids and bases react quantitatively with each other. When reacted in water, the neutralization effect works because there is no excess hydrogen or hydroxide ions in the solution.
A neutralization reaction is when an acid and a base react to form a salt with water, and H+ and OH ions mix to form water. Neutralizing strong acids and strong bases results in a pH of 7.
The reaction between an acid and a base is called a neutralization reaction, which can be thought of as a kind of substitution reaction in which the protons of an acid are replaced while being given to another species.
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24 points
Which two particles have opposite charges?
O A. lons and neutrons
B. Electrons and protons
OC. Neutrons and protons
OD. Electrons and neutrons
Answer:B
Explanation: according to the law of electrostatics it states that "unlike charge attract each other and like charges repel each other ".
q12 (1pts) which one of the following molecules has an atom with an incomplete octet? a) nf3 b) h2o c) ascl3 d) geh4 e) bf3
The following molecules has an atom with an incomplete octet is BF₃.
the following molecules given as follows :
a) NF₃ - it follow the octet rule. all the atom present have there octet complete. the molecule is stable;
b) H2O - all the have complete octet.
c) AsCl₃ - all the atoms have 8 electron in valence shell and follow octet rule.
d) GeH₄ - thos molecule also follow the octet rule
e) BF₃ - not follow the octet and have incomplete octet. Boron atom have in complete octet.
thus, The following molecules has an atom with an incomplete octet is BF₃.
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a shorter, easier way to show chemical reactions, using symbols instead of words, is called a group of answer choices
A shorter, easier way to show chemical reactions, using symbols instead of words, is called a Chemical equation.
All the elements in chemistry have specific name and properties. Along with this, they all have a particular sign like Na for sodium, Ar for Argon and K for potassium.
Rather than writing the full name in words of the elements, we write only the symbols of the element along with the products and the reactants separated by using a arrow pointing towards products side.
For example,
Chemical reaction: Sodium hydroxide reacts with Hydrogen chloride to form Sodium chloride and water.
Chemical equation: NaOH + HCl → NaCl + H₂O.
So, as we can see from the example, the chemical equation is much more easier to understands and shorter.
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What element has the highest electrical conductivity?
Mg
H
He
CI
Helium(He) will have the highest electrical conductivity.
Magnesium (Mg) is a metal, so it is electrically conductive in nature, though not as much as hydrogen and helium.
Above certain temperatures, hydrogen(H) is also electrically conductive.
Helium(He) The ease with which an electric charge or heat can pass through a material is measured as conductivity. A conductor is a material that resists the flow of an electric current or thermal energy very little. Metals are generally good conductors of electricity.
Because chlorine(Cl) is a nonmetal, it has the lowest electrical conductivity.
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If the hydrogen atom emits red, blue-green, blue, and violet light, how many energy levels does it have in the visible region of the spectrum?.
If the hydrogen atom emits red, blue-green, blue, and violet light, 4 energy levels do it have in the visible region of the spectrum. Therefore, option B is correct.
What is the electromagnetic spectrum?The term electromagnetic spectrum can be defined as the range of frequencies of electromagnetic radiation and their respective photon energies and wavelengths.
Therefore, the four colors red, blue-green, blue, and violet light emitted by a hydrogen atom, are of four energy levels in the visible region of the electromagnetic spectrum.
Thus, option B is correct.
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Your question is incomplete, most probably your question was
If the hydrogen atom emits red, blue-green, blue, and violet light, how many energy levels does it have in the visible region of the spectrum?
A. 3
B. 4
C. 5
D. 6
