1.Consider the molecule azulene and
a) set the secular determinant for azulene within the huckel approximation and using the out of plane C2p orbitals as basis set.
b) Estimate pi electron binding energy within the Huckel approximation
c) Approximate the delocalization energy

Answers

Answer 1
Mark Brainliest please

Answer :

The Hückel approximation is used to determine the energies and shapes of the π
π
molecular orbitals in conjugated systems. Within the Hückel approximation, the covalent bonding in these hydrocarbones can be separated into two independent "frameworks": the σ
σ
-bonding framework and the the σ
σ
-bonding framework. The wavefunctions used to describe the bonding orbitals in each framework results from different combinations of atomic orbitals. The method limits itself to addressing conjugated hydrocarbons and specifically only π
π
electron molecular orbitals are included because these determine the general properties of these molecules; the sigma electrons are ignored. This is referred to as sigma-pi separability and is justified by the orthogonality of σ
σ
and π
π
orbitals in planar molecules. For this reason, the Hückel method is limited to planar systems. Hückel approximation assumes that the electrons in the π
π
bonds “feel” an electrostatic potential due to the entire σ
σ
-bonding framework in the molecule (i.e. it focuses only on the formation of π
π
bonds, given that the σ
σ
bonding framework has already been formed).


Related Questions

What does Gibbs free energy predict?
A. It predicts what the rate of the reaction will be.
B. It predicts how high the activation energy is.
C. It predicts if entropy will increase or decrease.
D. It predicts whether or not a reaction will be spontaneous.

Answers

Answer:

D. It predicts whether or not a reaction will be spontaneous.

Explanation:

What does Gibbs free energy (ΔG) predict? .

A. It predicts what the rate of the reaction will be. NO. ΔG is a thermodynamical parameter and it is not related to the kinetics of the reaction.

B. It predicts how high the activation energy is. NO. ΔG is a thermodynamical parameter and it is not related to the kinetics of the reaction.

C. It predicts if entropy will increase or decrease. NO. ΔG depends on the entropy but not the other way around.

D. It predicts whether or not a reaction will be spontaneous. YES. If ΔG < 0 the reaction is spontaneous and if ΔG > 0 the reaction is not spontaneous.

How many grams of aluminum is required to react with 75.0 ml of 2.50 M HCl?

Answers

Answer:

63 g Al is required to react with 35 mL of 2.50 M hydrochloric acid

I'm sorry if it's wrong, I tried.

Explanation:

A diagram representing the levels of organization within an organism is shown below.
Х
-5-

Which level of organization is dentified by X?
(1) cell
(2) tissue
(3) organ
(4) organ system

Answers

The answer is 2. Tissue

A diagram representing the levels of organization within an organism is X. The  level of organization is identified by X is tissue. Therefore, option 2 is correct.

What is tissue ?

The term "tissue" refers to a collection of cells or fluid that cooperate to carry out a particular function in the body. Examples of such cells include those found in the kidney, heart, or blood cells, which transport oxygen to and waste products away from the body's cells.

The Old French term tissue, which means "a ribbon, belt, or piece of woven stuff," is where the noun tissue originates. Tissue really means to "weave fabric strands" as a verb. Tissues are now thought of as the disposable paper used for packaging presents or blowing our noses.

They stand for a degree of cell differentiation and order in living things. The activities of tissues include respiration, digesting, and transportation. As a result, tissues are crucial for multicellular creatures.

Thus, option 2 is correct.

To learn more about tissue, follow the link;

https://brainly.com/question/17664886

#SPJ2

which sphere would this be found in?

Answers

that is correct…….. i think

Answer:

The answer you picked was right.

Explanation:

9 How many grams of O₂ are needed to produce 15.5 g Fe₂O3 in the following reaction? Fe(s) + O₂(g) → Fe₂O3 (s)​

Answers

Answer:

Explanation:

so u can work out the amount of moles in FeO3 by doing mr of fe3o3 is 55.8*3+16*3=215.4

moles= mass/mr so you do 15.5g/215.4=0.0719 moles

then using 1 to 1 ratio so O2 moles is 0.0719

then use the equation mass=mole*mr

so 0.0719*16=1.15g

hope this make sense :)

The graph shows a relationship between volume and temperature. Which of the following statements is true?

A.) The graph shows a directly proportional relationship between volume and temperature and represents Charles' Law.
B.) The graph shows an indirectly proportional relationship between volume and temperature and represents Boyle's Law.
C.) The graph shows an indirectly proportional relationship between volume and temperature and represents Gay-Lussac's Law.
4.) The graph indicates that when temperature is increased, volume decreases.​

Answers

Answer:

The graph shows a directly proportional relationship between volume and temperature and represents Charles' Law.

Explanation:

The relation between volume and temperature is given by :

Ideal gas law, PV = nRT

Where

P is pressure

V is volume

R is gas constant

T is temperature

As volume and temperature have direct relationship. Charles law states that there is a direct relationship between volume and temperature. The correct option is (a).

which is generally more soluble in water ammonium chloride or potassium chloride explain

Answers

Answer:

Ammonium chloride

Explanation:

because is a salt which is highly soluble in water than potassium

‏calculate total pressure on bodies under water surface?

Answers

Explanation: this is how to calculate pressure underwater, I'm not sure if it's what you're looking for.

FORMULA: P=hρg

The temperature of 10 kg of a substance rises by 55oC when heated. Calculate the temperature rise when 22 kg of the substance is heated with the same quantity of heat.

Answers

Answer:

The temperature rise is 25°C

Explanation:

The heat of a substance is obtained using the equation:

Q = m*S*ΔT

Where Q is heat in kJ, m is the mass of the susbtance, S is specific heat of the material and ΔT change in temperature.

Replacing:

Q/S = m*ΔT

As Q is constant because the heat is the same and S is the specific heat of the material (Constant). We can write:

m1*ΔT1 = m2*ΔT2

Where m is mass and ΔT change in temperature of 1, initial conditions of the substance and 2, final conditions of the substance.

Replacing:

m1 = 10kg

ΔT1 = 55°C

m2 = 22kg

ΔT2 = ?

10kg*55°C = 22kg*ΔT2

ΔT2 = 25°C

The temperature rise is 25°C

Given the following set of atoms, write a bond-line formula for a possible constitutional isomer for the compound. Show all formal charges and lone pairs.C atoms H atoms Other3 6 2 Br atoms

Answers

Answer:

Explanation:

Isomers are compounds with the same molecular formula but chemically distinctive structures. Compounds that vary in connectivity, or how the component atoms are related to one another, are known as constitutional isomers. They have distinct functional groups and bonding patterns according to the sequence in which the atoms are linked together.

From the information given:

The compound given is C₃H₆Br₂ and the constitutional isomer of the compound can be seen in the image attached below.

The formal charges are calculated as follows:

Formal charge = valence electron - 1/2(bonding electron) - lone electron

For Br:

Formal charge = 7 - 1/2(2) - 6

Formal charge = 7 - 1 - 6 = 0

For C:

Formal charge = 4 - 1/2(8) - 0

Formal charge = 4 - 4 = 0

For H:

Formal charge = 1 - 1/2(2)

Formal charge = 1 - 1 = 0

how many milliliters of 0.105 M HCL are needed to titrate 22.5 ml of 0.118 M NaOH to the equivalence point

Answers

0.118 is + 100 = 718


3. 78 mL of 2.5 M phosphoric acid is neutralized with 500 mL of potassium hydroxide. What is the
concentration of the base?

Answers

Hence, concentration of base is 1.17 M

A researcher accidentally spilled some sand into his beaker containing crystalline compound X. Knowing what he did about melting points, he was not worried about obtaining the melting point of compound X with a few grains of sand present. Why

Answers

Answer:

See explanation

Explanation:

If we look at the structure of X, we will discover that X is an organic compound. The compound will certainly have a much lower melting point than sand.

This is because, sand is composed of high melting point inorganic materials.

Hence, even though the researcher accidentally spilled some sand into the the beaker containing the crystalline substance X, he does not need to be perturbed since the melting point of X is much lower than that of sand

PLEASE ANSWER ASAP I WILL GIVE YOU BRAINLIEST AND GIVE FREEE POINTSSS AFTER
Describe each of the following types of reactions and give one example of each: combustion, synthesis, decomposition, single replacement, double replacement.

Answers

Explanation:

Combustion Reaction:-

A kind of chemical reaction in which a reaction between any combustible substance and an oxidizer takes place in order to form an oxidized product.

Eg: Fuel + O2 → CO2 + H2O.

The burning of charcoal is a combustion reaction.

Synthesis Reaction:-

A synthesis reaction occurs when two or more reactants combine to form a single product.

Eg: Na + Cl → NaCl

An example of a synthesis reaction is the combination of sodium (Na) and chlorine (Cl) to produce sodium chloride (NaCl).

Decomposition Reaction:-

A decomposition reaction occurs when one reactant breaks down into two or more products.

Eg: NaCl → Na + Cl

An example of a decomposition reaction is the breakdown of Sodium chloride to give sodium and chloride.

Single Replacement Reaction:-

A single replacement reaction, sometimes called a single displacement reaction, is a reaction in which one element is substituted for another element in a compound.

Eg: Zn + 2 HCl → 2 ZnCl + H2

The reaction between zinc metal and hydrochloric acid to produce zinc chloride and hydrogen gas is an example of a single-displacement reaction.

Double Replacement Reaction:-

A double replacement reaction is a type of chemical reaction that occurs when two reactants exchange cations or anions to yield two new products.

Eg: AgNO 3 + NaCl → AgCl + NaNO

The reaction between silver nitrate and sodium chloride to produce silver chloride and sodium nitrate is an example of a double-displacement reaction.

presented by Machar
Phosphorus pentachloride decomposes according to the chemical equation
PCI (9) PCI, (g) + Cl, (9) K = 1.80 at 250 °C
A 0.3723 mol sample of PCI; (g) is injected into an empty 4.25 L reaction vessel held at 250 °C.
Calculate the concentrations of PCI; (g) and PCI, (9) at equilibrium.
[PCI) =
M
[PC1,1 =
M

Answers

Answer:

bziAIauUahah-&&*££iijb tctctcyc

What what I put to answer this?

Answers

The correct answer is B

How many molecules are contained in 52.5 moles of C2H8?
please explain if you can

Answers

Answer:

3.1621 × 10²⁵ molecules

Explanation:

From the given information:

Moles of C2H8 = 52.5 moles

number of moles = mass/molar mass

molar mass of C2H8 = (6 *2) + (1*8)

= 12 + 8

= 20 g/mol

52.5 moles = mass of C2H8 / 20 g/mol

mass of C2H8 = 52.5 moles × 20 g/mol

mass of C2H8 = 1050 grams

Recall that;

1 mole = 6.023 × 10²³ molecules

∴ 52.5 moles of C2H8 = (52.5 × 6.023 × 10²³) molecules

=3.1621 × 10²⁵ molecules

What is the PH of a solution with a concentration of 5.2 x 10-8 M H3O?

Answers

Answer:

7.28

Explanation:

The pH of a solution can be found by using the formula

[tex]pH = - log [ { H_3O}^{+}][/tex]

From the question we have

[tex]ph = - log(5.2 \times {10}^{ - 8} ) \\ = 7.28399[/tex]

We have the final answer as

7.28

Hope this helps you

What is the molar mass of a substance

A) the mass in grams of one mole of a substance
B) the number of particles in one gram of a substance
C) the number of moles in one gram of a substance
D) the mass in grams of one particle of a substance

thank you :)

Answers

Answer:

A) the mass in grams of one mole of a substance.

Explanation:

The molar mass of a substance is the mass in grams of 1 mole of the substance. As shown in this video, we can obtain a substance's molar mass by summing the molar masses of its component atoms. We can then use the calculated molar mass to convert between mass and number of moles of the substance.

How much energy would it take to freeze 12.5 g of water?

Answers

30 minutes to be exact

The amount of energy needed to freeze 12.5 grams of water into ice is equals to 14.295 kilo joules.

How do we calculate energy?

Energy required to freeze water will be calculated by using the following equation as:

Q = mcT, where

m = mass of water = 12.5g = 0.0125kg

c = specific heat of water = 4.187 kJ/kg.K

T = temperature to freeze = 0 degree C = 273.15 K

On putting values we get,

Q = (0.0125)(4.187)(273.15)

Q = 14.295 kJ

Hence required amount of energy is 14.295 kJ.

To know more about absorbed energy, visit the below link:

https://brainly.com/question/26306578

A gas mixture being used to simulate the atmosphere of another planet consists of 320 mg of methane, 175 mg of argon, and 225 mg of nitrogen. Th e partial pressure of nitrogen at 300 K is 15.2 kPa. Calculate (a) the volume and (b) the total pressure of the mixture.

Answers

Answer:

The total pressure is 61.4 kPa, and the volume is 1.31 L.

Explanation:

Based on the given information, a gas mixture comprising 320 mg or 0.320 grams of CH4, 175 mg or 0.175 grams of Ar, and 225 or 0.225 grams of N. The number of moles of the gases presents within the mixture can be determined by using the formula,

Number of moles = Mass/ molecular mass

The molecular mass of methane is 16.04 grams per mole, the molecular mass of Argon is 40 grams per mole, and the molecular mass of Nitrogen is 28.02 grams per mole.

Now, the number of moles of CH4 is,

= 0.320 grams/ 16.04 grams per mole

= 0.0199 moles

The number of moles of Ar is,

= 0.175 grams/40 grams per mole

= 0.0044 moles

The number of moles of N2 is,

= 0.225 grams/28.02 grams per mole

= 0.0080 moles

The partial pressure of nitrogen given is 15.2 kPa or 0.15 atm. Thus, the partial pressure of other two gases will be,

CH4 = (15.2 kPa) (0.0199 moles)/(0.0080 moles)

= 37.8 kPa

Ar = (15.2 kPa) (0.0044 moles)/(0.0080 moles)

= 8.36 kPa

Therefore, the total pressure is 15.2 + 37.8 + 8.36 = 61.4 kPa or 0.606 atm

The total volume can be determined by using the formula,

V = nRT/P

Here n is the total number of moles of the gas, which is 0.0323 moles.

Now putting the values we get,

V = (0.0323 moles) (0.0826 atm*L/mol*K)(300 K)/(0.606 atm)

V = 1.31 L

Use the following balanced equation to answer the questions below.

Answers

2:1
3:3
are the answers in order

A peanut was burned in a calorimeter filled with 70g of water. The temperature
increased from 21°C to 87°C. How much heat was released by the peanut. The
specific heat of water is 4.18 J/gºC *

Answers

Answer:

[tex]heat = mc \triangle \theta \\ = 70 \times 4.18 \times (87 - 21) \\ = 19311.6 \: joules[/tex]

A mixture containing nitrogen, hydrogen, and iodine established the following equilibrium at 400 °C:2NH3(g) + 3I2(g) ⇌ N2(g) + 6HI(g)Use the information below to calculate Kc for this reaction.N2(g)+3H2(g)⇌2NH3(g) Kc1= 0.50 at 400CH2(g)+I2(g)⇌2HI(g Kc2= 50 at 400°C

Answers

Answer: The value of [tex]K_{c}[/tex] for this reaction is 250000.

Explanation:

The given equation is as follows.

[tex]2NH_{3}(g) + 3I_{2}(g) \rightleftharpoons N_{2}(g) + 6HI(g)[/tex]

[tex]N_{2}(g) + 3H_{2}(g) \rightleftharpoons 2NH_{3}(g); K_{c_{1}} = 0.50[/tex]   ... (1)

[tex]H_{2}(g) + I_{2}(g) \rightleftharpoons 2HI(g); K_{c_{2}} = 50[/tex]  ... (2)

To balance the atoms, multiply equation (2) by 3. Hence, the equation (2) can be re-written as follows.

[tex]3H_{2}(g) + 3I_{2}(g) \rightleftharpoons 6HI(g); K_{c_{2}} = (50)^{3}[/tex]  ... (3)

Now, subtract equation (1) from equation (3). So, the equation formed will be as follows.

[tex]3I_{2} - N_{2} \rightleftharpoons 6HI - 2NH_{3}[/tex]

This equation can also be re-written as follows.

[tex]3I_{2} + 2NH_{3} \rightleftharpoons N_{2} + 6HI[/tex]

This equation is similar to the equilibrium equation given to us.

Therefore, during this subtraction the equation constants get divided as follows.

[tex]K^{'}_{c} = \frac{K_{c_{2}}}{K_{c_{1}}}\\= \frac{(50)^{3}}{0.50}\\= 250000[/tex]

Thus, we can conclude that the value of [tex]K_{c}[/tex] for this reaction is 250000.

Give the definition for diffusion. Group of answer choices gas molecules mix equally average distance between collisions gas molecules escape from a container into a vacuum through a small hole gas molecules mix unequally gas molecules spread out in response to a concentration gradient Next

Answers

Answer:

gas molecules spread out in response to a concentration gradient.

Explanation:

Diffusion can be defined as the movement of gas molecules from a region of high concentration to a region of lower concentration until an equilibrium is attained or reached. This mixing of gas molecules in the liquid or gaseous state is due to their kinetic energy of random motion i.e without requiring bulk motion.

This ultimately implies that, diffusion is a phenomenon through which gas molecules in either a gaseous or liquid state spread out in response to a concentration gradient, which is simply the difference in concentration of the gases across a space.

In conclusion, increasing the surface area of a gas increases its collision rate and it's considered to be an evolutionary strategy that maximizes the diffusion of gas molecules by catalysing the rate of a gaseous reaction.

A 0.2264 g sample of a pure carbonate, XnCO3(s) , was dissolved in 50.0 mL of 0.1800 M HCl(aq) . The excess HCl(aq) was back titrated with 24.90 mL of 0.0980 M NaOH(aq) . How many moles of HCl react with the carbonate

Answers

Answer:

6.56x10⁻³ mol

Explanation:

First we calculate how many HCl moles are there in 50.0 mL of a 0.1800 M solution:

0.1800 M * 50.0 mL = 9.00 mmol HCl

Then we need to calculate how many HCl moles were in excess, that number is the same as the number of NaOH moles they reacted with:

0.0980 M * 24.90 mL = 2.44 mmol NaOH = 2.44 mmol HCl

Finally we calculate the difference between the original number of HCl moles and the number remaining after the reaction with XnCO₃:

9.00 mmol - 2.44 mmol = 6.56 mmol6.56 mmol / 1000 = 6.56x10⁻³ mol

how do I name cycloalkanes?

Answers

Answer:

[tex]{ \tt{aromatic \: alkanes}} \\ \\ { \underline{ \blue{ \tt{becker⚜jnr}}}}[/tex]

1. Determine the number of sides of the cyclic compound.

2. Use IUPAC theory, determine the functional group and its position.

Metallic Bond
When nitrogen shares electrons with oxygen, what kind of bond is made?

Answers

Answer: covalent bonds

Explanation:

The solubility of CaSO4 in pure water at 0oC is 1.09 gram(s) per liter. The value of the solubility product is g

Answers

Answer: See image attached!

Good luck with your future exams!

The value of the solubility of product for CaSO₄ in pure water at 0 °C is 1.1881

What is solubility of product?

The solubility of product (Ksp) is defined as the concentration of products raised to their coefficient coefficients. This is illustrated below:

mA <=> nC + eD

Ksp = [C]^n × [D]^e

With the above information in mind, we can obtain the solubility of the product. This is illustrated below:

Dissociation equation

CaSO₄(aq) → Ca²⁺(aq) + SO₄²⁻(aq)

From the balanced equation above,

1 mole of CaSO₄ contains 1 mole of Ca²⁺ and 1 mole of SO₄²⁻

How to determine the concentration of Ca²⁺ and SO₄²⁻

From the balanced equation above,

1 mole of CaSO₄ contains 1 mole of Ca²⁺ and 1 mole of SO₄²⁻

Therefore,

1.09 g/L of CaSO₄ will also contain

1.09 g/L of Ca²⁺1.09 g/L of SO₄²⁻

How to determine the solubility of product Concentration of Ca²⁺ = 1.09 g/L Concentration of SO₄²⁻ = 1.09 g/L Solubility of product (Ksp) =?

CaSO₄(aq) → Ca²⁺(aq) + SO₄²⁻(aq)

Ksp = [Ca²⁺] × [SO₄²⁻]

Ksp = 1.09 × 1.09

Ksp = 1.1881

Learn more about solubility of product:

https://brainly.com/question/4530083

he specific heat capacity of a pure substance can be found by dividing the heat needed to change the temperature of a sample of the substance by the mass of the sample and by the change in temperature. The heat capacity of a certain substance has been measured to be

Answers

Complete question is;

The specific heat capacity of a pure substance can be found by dividing the heat needed to change the temperature of a sample of the substance by the mass of the sample and by the change in temperature. The specific heat capacity of a certain substance has been measured to be 3.52 J/g°C. Suppose 420.0 g of the substance is heated until the temperature of the sample has changed by 43.8 °C.

Write an equation that will let you calculate the last Q that was needed for this temperature change. Your equation should contain only symbols. Be sure to define each symbol.

Answer:

Q = m•c•Δt

Q = 64753.92 J

Explanation:

We are given;

Mass (m) = 420 g

Change in temperature; (Δt) = 43.8 °C

Specific heat capacity (c) = 3.52 J/g °C

The last Q is simply the heat energy that caused that temperature change.

This is given by the formula;

Q = m•c•Δt

Plugging in the relevant values;

Q = 420 × 3.52 × 43.8

Q = 64753.92 J

Other Questions
If a light beam strikes a shiny object at a 90-degree angle, to what are the angle of incidence and the angle of reflection equal? Help me!!! Find the domain of the function. Write the answer in interval notaion. These are my last 2 questionscan someone please help me with them Many Native American groups disappeared from Texas for all of the following reasons except:a.Anglo settlers forced them out.b.Native Americans could no longer find adequate food in Texas.c.Many Native American groups moved from Texas to Oklahoma.d.Native Americans died from new diseases that other settlers brought to Texas. The following are major factors in multinational cost of capital except: Group of answer choices Extent of international diversification of firm. Access to international capital markets. Size of the firm. Exposure to country risk. Exposure to credit risk or interest rate risk. A cylindrical juice container has the dimensions shown below.What is the exact volume of this container in terms of pi?A. 127 in?B. 271 inC. 811 in?D. 3241 in9in3in Between 2003 and 2005, there was huge growth in the market for premium blue jeans priced at $200 or more per pair. Popular magazines showing celebrities wearing certain brands largely fueled the growth. Then, in the summer of 2005, major department stores started cutting prices on the jeans; they were also found on websites that offer jeans at discount prices. Use the economic concepts that you learned to describe what is happening in this market. Label each image as containing atoms only,molecules that are not compounds, or compounds. Explain the purpose of fear in excelling in life? In a poll, respondents were asked whether they had ever been in a car accident. 259 respondents indicated that they had been in a car accident and 442 respondents said that the had not been in a car accident. If one of these respondents is randomly selected, what is the probability of getting someone who has been in a car accident An erect electric pole is 7m away from the ground. It casts a shadow on the horizontal ground when the altitude of the sun is 60 calculate the length of the shadow The price of an item has been reduced by 20%. The original price was $35. What is the price of the item now? If the activation energy required for a chemical reaction were reduced, what would happen to the rate of the reaction?The rate would increase.The rate would decrease.The rate would remain the same.The rate would be zero.Mark this and returnSave and ExitNeesSubmit i am stuck under my bed please help The heights of two different children were recorded in the chart.What type of visual display could be used to compare the two data sets?box-and-whiskerscatter plotneither of theseboth of these Huntington disease is caused by the inheritance of a dominant allele for a gene that affects the brain. The symptoms of the disease include the lossof mental abilities and muscle coordination A football player kicks a ball of mass 450 g with a force of 1500 N. The contact time of his shoe with the ball is 0.008 s. If the contact time is increased to 0.013 s , what is the velocity of the ball ? Why would it be a bad thing for workers (especially children) to be doing double the work during their shifts? (Think baout trying to manage two machines at one time) PLEASE HELP ASAP - ILL GIVE BRAINLIEST Which of the following never cause a change in the motion of an object? O A. Net forces O B. Unbalanced forces C. Balanced forces D. Contact forces