Answer:
-15.5 kJ/mol
Explanation:
2A ⇄ 2B + C
[tex]$ K = \frac{[C][B]^2}{[A]^2} $[/tex]
= [tex]$ \frac{(0.69)(0.49)^2}{0.88^2} $[/tex]
= 0.21
T = [tex]$ 43.9^{\circ} $[/tex]C
= (273 + 43.9) K = 316.9 K
[tex]$ \Delta G^{\circ} = -19.4 $[/tex] kJ/mol
R = 8.314 J/k-mol = 0.008314 kJ/k-mol
[tex]$ \Delta G = \Delta G^{\circ} - RT \ln K $[/tex]
[tex]$ =-19.4 - 0.008314 \times 316.9 \ln (0.21) $[/tex]
= -15.5 kJ/ mol
What is the final product of the following sequence of reactions? (CH3NCHOH PBr3 Mg diethyl ether 1) L N PCC 2) H3O * CH2Cl2 A) (CH3)2CHOCH2CH2OH. B) (CH3)2CHCCH3C) (CH3)2CHCH2CHO.D) (CH3)2CHCH2CO2H.
Answer:
(CH3)2CHCH2CHO
Explanation:
The reaction sequence begins with the reaction of isopropanol with phosphorus tribromide to yield isopropyl bromide. This is followed by reaction with Magnesium in ether solution giving a grignard reagent, isopropyl magnesium bromide. This is now attacked by oxirane and the epoxide ring opens, hydrolysis of the product, followed by oxidation using pyridinium chlorochromate (PCC) yields the final product- (CH3)2CHCH2CHO
The detailed reaction mechanism is attached to this answer.
To convert m-ethylaniline to m-ethylfluorobenzene, it should be treated with nitrous acid followed by _____________.
Answer:
[tex]NaBF_4[/tex]
Explanation:
In this reaction, we must exchange the amino group ([tex]NH_2[/tex]) for a fluorine atom ([tex]F[/tex]). Also, the first step in this reaction is the addition of nitrous acid.
We must remember that the amino group in the presence of nitrous acid produces a diazonium salt. The [tex]N_2[/tex] group is a very good leaving group and many benzene derivatives can be produced from this intermediate (see figure 1).
If what we want is to bond a fluorine atom we must use [tex]NaBF_4[/tex] to be able to produce m-ethylfluorobenzene (see figure 2).
I hope it helps!
Which of these are not true statements a compound?
A compound's properties are usually not the same as the properties of the elements that make it up.
A compound always has the same composition.
A compound is made up of more than one type of atom.
A compound can have more than one chemical formula and still be considered the same compound.
Answer:
A compound can have more than one chemical formula and still be considered the same compound.
Explanation:
Which of these are not true statements a compound?
A compound's properties are usually not the same as the properties of the elements that make it up. TRUE. For instance, the salt NaCl has different properties than the solid metal Na and the gaseous nonmetal Cl₂.
A compound always has the same composition. TRUE. The ratio of elements in a compound is constant.
A compound is made up of more than one type of atom. TRUE. Unlike elements, compounds are formed by 2 or more elements.
A compound can have more than one chemical formula and still be considered the same compound. FALSE. Each compound can have only one chemical formula.
This equation shows the reaction of trans-2,3-dimethyloxirane with hydrogen chloride to form 3-chloro-2-butanol.
how many total stereoisomer are possible for 3-Chloro-2-butanol?
Given that opening of the epoxide ring in this reaction is stereoselective, provide the names of the only two isomeric products using IUPAC guidelines.
Product one: _______ 3-chloro-2-butanol
Product two: _______3-chloro-2-butanol
Answer:
Product one: (2S, 3R)-3-chloro-2-butanol
Product two: (3S, 2R)-3-chloro-2-butanol
Explanation:
The IUPAC name of the products following IUPAC guidelines are :
Product one: (2S, 3R)-3-chloro-2-butanol
Product two: (3S, 2R)-3-chloro-2-butanol
attached below is a pictorial representation of the formation of the 3-chloro-2-butanol via backside attack of Nucleophile
A piece of wood that measures 3.0 cm x 6.0 cm x 4.0 cm has a mass of 80.0 g. What is the density of the word? With a piece of wood float in the water? Volume equals length times with times height
Answer : The density of wood is 1.11 g/cm³.
The piece of wood will not float in water.
Explanation : Given,
Mass of wood = 80.0 g
Length of piece of wood = 3.0 cm
Width of piece of wood = 6.0 cm
Height of piece of wood = 4.0 cm
First w have to calculate the volume of wood.
Volume of wood = Length × Width × Height
Volume of wood = 3.0 cm × 6.0 cm × 4.0 cm
Volume of wood = 72.0 cm³
Now we have to calculate the density of wood.
[tex]\text{Density of wood}=\frac{\text{Mass of wood}}{\text{Volume of wood}}[/tex]
Now putting all the given values in this formula, we get:
[tex]\text{Density of wood}=\frac{80.0g}{72.0cm^3}[/tex]
[tex]\text{Density of wood}=1.11g/cm^3[/tex]
As we know that there are two conditions to determine whether the object will float or sink in a liquid.
If the density of object is less than water then the object will float on water.If the density of object is more than water then the object will sink in water.The density of water is 1 g/cm³.
From this we conclude that the density of wood is more than water that means the wood will sink in water.
Determine the pH of a solution of 0.00278 M of HClO4. Report the answer to two digits past the decimal.
Answer:
The pH of a solution of 0.00278 M of HClO₄ is 2.56
Explanation:
pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance and is calculated as:
pH= - log [H⁺]= - log [H₃O⁺]
On the other hand , a Strong Acid is that acid that in an aqueous solution dissociates completely. In other words, a strong acid completely dissociates into hydrogen ions and anions in solution.
HClO₄ is a strong acid, so in aqueous solution it will be totally dissociated. Then, the concentration of protons is equal to the initial concentration of acid and the pH will be calculated:
pH= - log 0.00278
pH= 2.56
The pH of a solution of 0.00278 M of HClO₄ is 2.56
What is the wavelength for electromagnetic radiation with a frequency of 1.10 x 10 to the 6 hs?
Answer:
here is something I know
hope it works :)
Explanation:
Visible light has a wavelength range from ~400 nm to ~700 nm. Violet light has a wavelength of ~400 nm, and a frequency of ~7.5*1014 Hz. Red light has a wavelength of ~700 nm, and a frequency of ~4.3*1014 Hz.
Which statement is TRUE regarding the macroscopic and
microscopic nature of chemistry?
Chemists make observations on the macroscopic
a scale that lead to conclusions about microscopic
features
b
Changes that occur on the macroscopic scale affect
what we observe on the microscopic scale
Chemists make observations on the microscopic
C scale that lead to conclusions about macroscopic
features
d Chemists are only concerned with macroscopic
changes and features
Answer:
Chemists make observations on the macroscopic a scale that lead to conclusions about microscopic features
Explanation:
Many important chemical observations are made on the macroscopic scale. This is because, many of the scientific equipments available are not presently able to provide direct evidence about microscopic processes. Evidences obtained from macroscopic observations could serve as important insights into the nature of certain microscopic processes.
This is evident in the study of the structure of the atom. Most of the evidences that led to the deduction of the atomic structure were obtained from macroscopic evidence but ultimately provided important information about the microscopic structure of the atom.
It is true that Chemists make observations on the macroscopic scale that lead to conclusions about microscopic features.
Macroscopic observations are those that humans are able to see with their naked eyes.
Observing macroscopic phenomenon, scientists are able to come up with conclusions at a microscopic level because anything that happens at the macroscopic level is as a result of microscopic occurrences on a much smaller level.
Examples of macroscopic occurrences that lead to microscopic conclusions:
Water evaporating when heated allows scientists to conclude that atoms move faster when they gain heat Food decaying allows scientists to conclude that microscopic organisms are working on the food.In conclusion, the observations we make on a macroscopic scale allow for microscopic conclusions.
Find out more at https://brainly.com/question/2496507.
Consider the diprotic acid H2A with K1 = 1.00 x 10-4 and K2 = 1.00 x 10-8 . Find the pH and concentrations of H2A, HA-, and A2- in (a) 0.100 M H2A; (b) 0.100 M NaHA; (c) 0.100 M Na2A
Answer:
Explanation:
H₂A ⇄ HA⁺ + A⁻
K₁ = [ HA⁺] [A⁻ ] / [ H₂A ]
HA⁺ ⇄ H⁺ + A⁻
K₂ = [ H⁺] [ A ⁻ ] / [ HA⁺ ]
H₂A ⇄ HA⁺ + A⁻
.100 0 0
.100 - C C C
K₁ = [ HA⁺] [A⁻ ] / [ H₂A ]
Putting the values
1.00 x 10⁻⁴ = C X C / .1 - C
10⁻⁵ - 10⁻⁴ C = C²
C² + 10⁻⁴ C - 10⁵ = 0
C = 8 X 10⁻² M
So concentration of H₂A that is [ H₂A ] = 1 - C = 0 .1 - 8 X 10⁻² M
= .02 = 2 x 10⁻² M
NaHA ⇄ Na⁺ + HA⁻
NaHA is a strong acidic salt so it will ionise 100 %
NaHA ⇄ Na⁺ + HA⁻
.1 .1 .1
concentration of HA⁻ = .1 M
Na₂A ⇄ 2Na⁺ + A⁻²
Na₂A is also a strongly ionic salt so it will dissociate 100 % .
Na₂A ⇄ 2Na⁺ + A⁻²
.1 .1 .1
concentration of A⁻² = .1 M
HA⁺ ⇄ H⁺ + A⁻
8 X 10⁻² C₁ C₁
K₂ = [ H⁺] [ A ⁻ ] / [ HA⁺ ]
Putting the values
1.00 x 10⁻⁸ = C₁ X C₁ / C
1.00 x 10⁻⁸ = C₁² / 8 X 10⁻²
C₁² = 8 x 10⁻¹⁰
C₁ = 2.828 x 10⁻¹⁰
[ H⁺] = 2.828 x 10⁻¹⁰
pH = - log [ H⁺] = - log 2.828 x 10⁻¹⁰
= 10 - log 2.828
= 10 - .45
= 9.55 .
Know about the first model of the atom.
Answer:
The ancient Greeks were the first to use the word atom,which means indivisible,to describe the smallest particle of any substance. Its actual existence was not established until yhe nineteenth century when John Dalton, an English chemist,put forward a theory to describe the nature of the atom.The atom is now considered to be the basic unit of simple substances or elements.An atom is the smallest particle of an element which can take part in a chemical reaction or an atom is the smallest part of an element that can ever exist and still possess the chemical properties of that element.
A sample of nitrogen gas is confined to a 14.0 L container at 375 torr and 37.0°C. How many moles of nitrogen are in the container?
Answer:
n = 0.271 moles
Explanation:
Given that,
Volume of container, V = 14 L
Pressure of Nitrogen gas, P = 375 torr
Temperature. T = 37°C=37+273=310°C
We need to find the number of moles of nitrogen in the container. Using gas equation,
PV = nRT
R is gas constant, R = 0.082 L-atm/mol-K
Since, 1 atm=760 torr
375 torr = 0.493 atm
Now,
[tex]n=\dfrac{PV}{RT}\\\\n=\dfrac{0.493\times 14}{0.082\times 310}\\\\n=0.271[/tex]
So, there are 0.271 moles of Nitrogen in the container.
The ideal gas law, also called the general gas equation, is the equation of the state of a hypothetical ideal gas.
The ideal gas law work under the constant:-
Pressure Temperature Volume
Hence the formula we gonna use is as follows:-
[tex]PV = nRT[/tex]
In the question, the pressure, temperature, and volume are given in two different systems.
As the date given in the question, after putting it into the equation:-
[tex]n= \frac{PV}{RT}[/tex]
[tex]n = \frac{0.493*14}{0.082 *310}[/tex]
n= 0.271.
The number of moles in the nitrogen container is 0.271.
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a sample of mass 6.814grams is added to another sample weighing 0.08753 grams. the subsequent mixture is then divided into exactly 3 equal parts. one of those parts has the yield multiplied by 7.6335 times, what is the final mass?
Answer:
[tex]Final\ Mass = 17.560943085g[/tex]
Explanation:
Given
[tex]Sample\ Mass = 6.814g[/tex]
[tex]Additional\ Mass = 0.08753g[/tex]
[tex]Yield = 7.6335[/tex]
Required
Determine the final mass
First we need to determine the total mass after the sample mass is added to an additional sample;
[tex]Total\ Mass = Additional\ Mass + Sample\ Mass[/tex]
[tex]Total\ Mass = 0.08753g + 6.814g[/tex]
[tex]Total\ Mass = 6.90153g[/tex]
Next, divide the total mass by 3
[tex]New\ Mass = \frac{Total\ Mass}{3}[/tex]
[tex]New\ Mass = \frac{6.90153g}{3}[/tex]
[tex]New\ Mass = 2.30051g[/tex]
The final mass is calculated as follows;
[tex]Final\ Mass = New\ Mass * Yield[/tex]
[tex]Final\ Mass = 2.30051g * 7.6335[/tex]
[tex]Final\ Mass = 17.560943085g[/tex]
Hence, the final mass is 17.560943085g
Which measurement of length is the smallest?
9 10–6 m
7 10–5 m
7 101 m
9 102 m
Answer:
A is the correct answer
A is the correct answer
The main type of attractive forces between molecules of carbon tetrabromide (cbr4) are:_______
Answer:
Vanderwaals forces
Explanation:
CBr4 is a nonpolar molecule, nonpolar molecules usually possess vanderwaals forces between their molecules as their main attractive force.
CBr4 is nonpolar because the tetrahedral arrangement of the C-Br bonds cancel out the individual dipole moments of each C-Br bond thereby making the compound nonpolar, hence the answer above.
What fundamental unit of the metric system always has a prefix in front of it?
Answer:
Kilogram
Explanation:
The metric system is the Kilogram, meter, second system. These are fundamental quantities of the metric system.
Kilogram, the unit of mass always carries the prefix 'kilo' in its SI unit. Kilogram is the SI unit of mass. Hence, the fundamental unit on the metric system that always has a prefix in front of it is kilogram.
the rate of disappearance of Br- at some moment in time was determined to be 3.5 x 10-4 M/s. What is the rate of appearance of Br2 at that same moment
Answer:
1.8 × 10⁻⁴ mol M/s
Explanation:
Step 1: Write the balanced reaction
2 Br⁻ ⇒ Br₂
Step 2: Establish the appropriate molar ratio
The molar ratio of Br⁻ to Br₂ is 2:1.
Step 3: Calculate the rate of appearance of Br₂
The rate of disappearance of Br⁻ at some moment in time was determined to be 3.5 × 10⁻⁴ M/s. The rate of appearance of Br₂ is:
3.5 × 10⁻⁴ mol Br⁻/L.s × (1 mol Br₂/2 mol Br⁻) = 1.8 × 10⁻⁴ mol Br₂/L.s
Blue light waves have more energy than red light waves. Which of theses situations most likely produces a photoelectric effect? You may assume that the same metal is used in each situation. Check all that apply.
-shining dim red light on a strip of metal
-shining bright red light on a strip of metal
-shining dim blue light on a strip of metal
-shining bright blue light on a strip of metal
The correct options are: shining dim blue light on a strip of metal, and
shining bright blue light on a strip of metal produces a photoelectric
effect. Hence, option (C) and (D) are correct
What is Photoeletric effect ?The photoelectric effect is the emission of electrons from a metallic surface when light of determined frequency shines over the metallic surface.
The electrons are ejected from the metal surface when the frequency of the incident light beam reaches a minimum frequency (threshold).
The frequency of light is related to the color of light (not with the intensity).
The red light is at the lower frequency end and the violet light at the higher frequency end of the spectrum of visible light.
That condition is considered in the given statement when it tells that "Blue light waves have more energy than red light waves" , since the frequency is directly related to the energy, by the Planck equation:
Energy of a photon (light) = Planck constant × frequency.
The intensity of the light (if the light is dim or bright) does not influence the photoelectric effect.
Hence, you conclude that the light with more energy (the blue light) either dime or bright will most likely produce the photoelectric effect.
That is why the correct options are:
shining dim blue light on a strip of metal, andshining bright blue light on a strip of metalLearn more about Photoelectric effect here ;
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Calculate the molar mass of calcium hydroxide, Ca(OH),(s). Write your answer using
proper units. Show all work.
Answer:
57.09 g/mol
Explanation:
Step 1: Find the mass for every 1 mole in each element
Ca - 40.08 g/mol
O - 16.00 g/mol
H - 1.01 g/mol
Step 2: Add the masses to find total mass
40.08 + 16.00 + 1.01 = 57.09 g/mol
So we have 57.09 grams per every mole in Calcium Hydroxide.
identify A
CH3CL+AgCN-----??(A)
Your question has been heard loud and clear
CH3Cl + AgCN = CH3CN + AgCl
A= CH3CN+AgCl
Thank you
What do you think pseudo- means?
Pseudo in chemistry means a reaction which is not first-order reaction naturally but made first order by increasing or decreasing the concentration of one or other reactant is known as Pseudo first order reaction.Pseudo means "fake".
If there are 17.5 grams of sugar in 225 grams of an aqueous sugar solution, the percent-mass sugar is
Answer:
% m/m (sugar) = 7.77 %
Explanation:
Step 1: Given data
Mass of sugar (solute): 17.5 g
Mass of solution: 225 g
Step 2: Calculate the percent by mass of sugar
The percent by mass of sugar is equal to the mass of sugar divided by the mass of the solution times 100%.
% m/m (sugar) = (mass of sugar / mass of solution) × 100%
% m/m (sugar) = (17.5 g / 225 g) × 100%
% m/m (sugar) = 7.77 %
You need to make an aqueous solution of 0.237 M chromium(III) acetate for an experiment in lab, using a 500 mL volumetric flask. How much solid chromium(III) acetate should you add
Answer: 27.1 g of solid chromium(III) acetate should be added.
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in ml
moles of [tex]Cr(CH_3COO)_3[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{xg}{229g/mol}[/tex]
Now put all the given values in the formula of molality, we get
[tex]0.237=\frac{xg\times 1000}{229g/mol\times 500ml}[/tex]
[tex]x=27.1[/tex]
Therefore, 27.1 g of solid chromium(III) acetate should be added.
ΚΕ:
m.22
2
What is the kinetic energy of 10kg dog running with a velocity of 12m/s?
Answer:
The answer is
720 JoulesExplanation:
The kinetic energy of a body can be found by using the formula
[tex]K.E = \frac{1}{2} {mv}^{2} [/tex]where
m is the mass
v is the velocity / speed
From the question
mass = 10 kg
velocity = 12 m/s
Substitute the values into the above formula and solve
That's
[tex]KE = \frac{1}{2} \times 10 \times {12}^{2} \\ = 5 \times 144 \: \: [/tex]We have the final answer as
720 JoulesHope this helps you
This is really hard help pls
The answers are A. Pseudoscience is often based only on opinions; D. Pseudoscience often involves explanations of beliefs; E. Pseudoscience includes subjective ideas.
Explanation:
Pseudosciences comprises disciplines or theories that do not follow scientific standards but claim to be factual. This includes areas such as clairvoyance or astrology because this is not based on evidence but subjectivity. Indeed, the base of most pseudosciences are personal beliefs, opinions, or subjective ideas. Moreover, complex theories or methods are created to try to explain these beliefs, but because they do not follow scientific standards they are not considered as valid. In this context, options A, D, and E are correct.
Question 4 of 10
Which phrase best describes how scientists use the data they collect?
A. To convince students to repeat their experiments
B. To prove that a scientific hypothesis is correct
C. To persuade other people to believe the same things
D. To decide if there is support for an experiment's conclusions
Answer:
D.
Explanation:
Apex
Scientists use the data which they collect to decide if there is support for an experiment's conclusions and to test if it is in support or against the hypothesis proposed.
What is hypothesis?Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
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When you have a free metal ion, how do the energies of these orbitals relate to one another (are they the same, different, etc.)?
Answer:
The energy of the orbitals are the same
Explanation:
For a free metal ion, all the d-orbitals are of the same energy. The five d-orbitals are said to be five fold degenerate in the free metal ion. Hence all the d-orbitals will possess the same energy irrespective of which one is first filled.
In an octahedral or tetrahedral crystal field, the d-orbitals will loose their degeneracy and become different in energy based on their orientation towards the ligands.
3. A block with a volume of 82.1 cm3 is made out of pure tin (Sn). If the mass of the block is
600. g, what is the density of the block?
Answer:
The answer is
7.3 g/cm³Explanation:
Density of a substance is given by
[tex]Density(\rho) = \frac{mass}{volume} [/tex]From the question
mass of block = 600 g
volume = 82.1 cm³
Substitute the values into the above formula and solve for the Density
That's
[tex]Density = \frac{600}{82.1} \\ = 7.3081607[/tex]We have the final answer as
7.3 g/cm³ to one decimal placeHope this helps you
Two solutions, initially at 24.60 °C, are mixed in a coffee cup calorimeter (Ccal = 15.5 J/°C). When a 100.0 mL volume of 0.100 M AgNO3 solution is mixed with a 100.0 mL sample of 0.200 M NaCl solution, the temperature in the calorimeter rises to 25.30 °C. Determine the ∆H°rxn in kJ/mol AgCl for the reaction as written below. The density of the final solution is 1.00 g/mL and heat capacity of the final solution is 4.18 J/goC.
NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq) H°rxn= ?
Answer:
ΔH = -59.6kJ/mol
Explanation:
The reaction that occurs between Ag⁺ and Cl⁻ ions is:
Ag⁺ + Cl⁻ → AgCl(s) + ΔH
To find ΔH we need to obtain moles of reaction and heat released in the reaction because ΔH is defined as heat released per mole of reaction.
Moles of reaction:
Moles of Ag⁺ and Cl⁻ added are:
Ag⁺: 0.100L * (0.100mol / L) = 0.01moles
Cl⁻: 0.100L * (0.200mol / L) 0 0.02 moles
That means limiting reactant is Ag⁺ and moles of reaction are 0.01 moles
Heat released:
To find heat released we must use coffe cup calorimeter equation:
Q = C*m*ΔT
Where C is specific heat of solution (4.18J/g°C), m is the mass of solution (200g because there are 100 + 100mL = 200mL and density of solution is 1g/mL) and ΔT is change in temperature (25.30°C - 24.60°C = 0.70°C).
Replacing:
Q = C*m*ΔT
Q = 4.18J/g°C * 200g * 0.70°C
Q = 585,2J
Is total heat released.
The calorimeter absorbs:
15.5J / °C * 0.7°C = 10.85
Thus, when 0.01 moles reacts, 585.2J + 10.85 = 596.05J are released (Heat released is heat abosrbed by calorimeter + Heat absorbed by water) and ΔH is:
ΔH = 596.05J / 0.01 moles =
ΔH = 59605J / mol =
ΔH = -59.6kJ/molAs heat is released, ΔH < 0.
how many atoms are in 3.05 grams of copper?
6.02 x10^23 atom
3.5g x 1mol/63.55g Cu x 6.02 x 10^23/ 1mol=
3.32 x 10^22 atoms
NBr3 a) dispersion forces b) dipole-dipole forces c) hydrogen bonding
Answer:
b) dipole-dipole forces
Explanation:
Hello,
In this case, it is widely known that NBr₃ is a polar molecule since it has a trigonal pyramidal geometrical structure in which nitrogen has a lone pair of electrons and three bonds with three bromine atoms which are polar, due to the fact that bromine is less electronegative than nitrogen. causing the overall compound to be polar, as the dipoles are not cancelled. Therefore, the strongest forces are b) dipole-dipole forces among dipoles.
Regards.