Q 16.1: Select the first step in the Wittig reaction. A : The alkyltriphenylphosphonium halide is deprotonated by a base to make a phosphorus ylide. B : The phosphorus ylide reacts with the aldehyde or ketone to make an oxaphosphetane. C : Triphenylphosphine attacks the alkyl halide to produce an alkyltriphenylphosphonium halide. D : The oxaphosphetane decomposes to form the alkene and triphenylphosphine oxide.

Answers

Answer 1

Answer:

The phosphorus ylide reacts with the aldehyde or ketone to make an oxaphosphetane.

Explanation:

The Wittig reaction is a reaction that occurs between a phosphorus ylide and an aldehyde or ketone. The final products are an alkene and triphenyl phosphine oxide.

The first step in the reaction is the attack of the phosphorus ylide on the aldehyde or ketone. This is followed by attack of oxygen on phosphorus to form a [2+2] cycloaddition product (oxaphosphetane)  which  decomposes to form the alkene and triphenylphosphine oxide.


Related Questions

HELPPPPPPPPP 35 POINTSSSSSS!!!!!
A metal is oxidized if it’s converted from its metallic form to make a compound, and it’s reduced if it’s converted back to its metallic form.
FILL IN THE BLANKS with either "reduce" or "oxidize"
Magnesium is able to copper, and copper is able to magnesium.
Zinc is able to magnesium, and magnesium is able to zinc.
Copper is able to zinc, and zinc is able to copper.

Answers

Answer:

oxidize

Explanation:

A mixture is prepared using 27.00 mL of a 0.0758 M weak base (pKa=4.594) , 27.00 mL of a 0.0553 M weak acid (pKa=3.235) and 1.00 mL of 1.25×10−4 M HIn and then diluting to 100.0 mL, where HIn is the protonated indicator. The absorbance measured at 550 nm in a 5.000 cm cell was 0.1102 . The molar absorptivity (????) values for HIn and its deprotonated form In− at 550 nm are 2.26×104 M−1cm−1 and 1.53×104 M−1cm−1 , respectively. What is the pH of the solution?

Answers

Answer:

pH = 4.164

Explanation:

The first process is to find the initial moles for the base (B) & the acid (HA)

i.e.

[tex]= \dfrac{27 mL \times 0.0758 \ moles \ \ of \ B}{1000 \ mL}[/tex]

[tex]=0.0020466[/tex]

[tex]\simeq 2.047\times 10^{-3} \ moles \ of \ B[/tex]

[tex]= \dfrac{27 mL \times 0.0553 \ moles \ \ of \ HA}{1000 \ mL}[/tex]

[tex]=0.0014931[/tex]

[tex]\simeq 1.493\times 10^{-3} \ moles \ of \ HA[/tex]

The acid with base reaction is expressed as;

          HA              +      B         →             A⁻            +         HB⁺

to    1.493 × 10⁻³       2.047 × 10⁻³             -                         -

    -  1.493 × 10⁻³       1.493 × 10⁻³         1.493 × 10⁻³         1.493 × 10⁻³

            0                    5.54 × 10⁻⁴         1.493 × 10⁻³         1.493 × 10⁻³

From observation; both the acid & base weak

Given that:

The pKa for base = 4.594

The pKa for acid = 3.235

Recall that;

pKa = -log Ka

So; Ka = [tex]\mathbf{10^{-Ka}}[/tex]

By applying this:

For Base; Ka = [tex]10^{-4.594}[/tex] = 2.5468 × 10⁻⁵

For Acid:  Ka = [tex]10^{ -3.235}[/tex] = 5.821 × 10⁻⁴

After the reaction; we have the base with its conjugate acid & conjugate base of acid; Thus, since the conjugate acid of the base possesses a higher value of K, it is likely it would be the one to define the pH of the solution.

By analyzing the system, we have:

              HB⁺         + H₂O           ↔           B          +            H₃O⁺

     [tex]\dfrac{1.493\times 10^{-3}}{0.1 \ L}[/tex]                                 [tex]\dfrac{5.54\times 10^{-4}}{0.1 \ L}[/tex]

to   0.01493 M                                 0.00554   M

  -      x                                                   x                                x

    0.01493 - x                                 0.00554 - x                     x

Thus;

[tex]2.5468 \times 10^{-5} = \dfrac{(0.00554 -x)\times x}{(0.01493-x)}[/tex]

Using the common ion effect;

0.00554 - x   [tex]\simeq[/tex]  0.00554   &

0.01493 -  x   [tex]\simeq[/tex]   0.01493

[tex]x = \dfrac{2.5468 \times 10^{-5} \times 0.01493}{0.00554}[/tex]

x =  [H₃O⁺] = 6.8635  × 10⁻⁵

pH = -log(6.8635  × 10⁻⁵)

pH = 4.164

PLEASE HELP ME!!!!!!!!

Answers

Answer:

I think the answer is false

I think the answer is true am not sure tho.

I NEED TO KNOW THIS ASAP

Answers

Answer:

I think that the answers A, not 100% sure tho

Explanation:

Because the problem says "highly radioactive" chemicals and gamma rays are highly radioactive chemicals, and gamma rays are very penetrating to the human body

I would have to say c) hopefully this is a right!:)

Which is a factor that keeps Earth in orbit around the Sun? the moon O the gravitational pull of the Sun the continuous motion of the universe Earth's changing speed and direction ctivity​

Answers

Answer:

The Sun's gravitational pull keeps our planet orbiting the Sun. The motion of the Moon is affected by the gravity of the Sun AND the Earth. The Moon's gravity pulls on the Earth and makes the tides rise and fall every day. As the Moon passes over the ocean, there is a swell in the sea level.

Explanation:

The statement of factor that keeps Earth in orbit around the Sun is "the gravitational pull of the Sun."

What is the Sun and the Earth?

The Sun is the primary star of our Solar System. The Earth revolves around our Sun, which really is a star. At a distance of around 93 million miles from the Sun, Earth is the third planet.

The fundamental force that governs the planets' orbits around the sun is gravity. While each planet does have its own gravity, which is determined by its size and speed of movement, orbit is determined by the gravity of the sun.

Our planet orbits the Sun due to it's gravitational pull. The Sun, as well as all of the planets and moons, are gravitationally bound together and circle all around solar system's centre of gravity.

The Sun's gravity is around 27.9 times that of Earth's, and it helps to govern the tides on Earth in a modest degree.

Hence the correct answer is the gravitational pull of the Sun.

Learn more about Sun and Earth here

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why do chemist synthesize polymers in the lab?

Answers

The reason why chemists synthesize polymers in the lab is;

because of the need to perform and observe the results of a variety of synthesized polymer reactions and to predict when a reaction will happen.

      Polymers are simply defined as a substance or material made up of long repeating chemical chains of molecules.

     Now, polymer synthesis is simply called polymerization and it is the process by which smaller molecules called monomers undergo covalent bonding to form a longer polymer chain.

      Now, from the definition above, the reason why chemists synthesize polymers in the lab is because of the need to perform and observe the results of a variety of synthesized polymer reactions and to predict when a reaction will happen.

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Choose all the right answers.

Why do all machines lose some energy while they operate?

They run out of fuel.
Some heat radiates out.
Moving parts cause friction.
High pressure gases move the piston.

Answers

They run out of fuel
Some heat radiates out
High pressure gases move the piston

Answer:

They run out of fuel

Some heat radiates out

High pressure gases move the piston

When the volume of a gas is
changed from 3.6 L to 15.5 L, the
temperature will change from
°C to 87°C.
Assume that the number of moles and the
pressure remain constant.
Be sure to notice that temperatures are
given in °C!

Answers

Answer:

-189.55°C

Explanation:

Given data:

Initial volume of gas = 3.6 L

Final volume of gas = 15.5 L

Initial temperature = ?

Final temperature = 87°C (87+273 = 360 K)

Solution:

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

T₁  = V₁T₂  /V₂

T₁   = 3.6 L × 360 K / 15.5 L

T₁   = 1296 L.K / 15.5 L

T₁  = 83.6 K

Kelvin to °C:

83.6 K - 273.15 = -189.55°C

What is the name of Bel on the periodic table

Answers

Answer:

Nobelium or Beryllium

Which statement is true about copper and salt?

Answers

Well there aren’t any statements but, Salt and Copper are pure substances they aren't a part of a mixture on their own I hope this helps

What is another name for acetic acid? *
1. lemons, limes or oranges
2 .vinegar
3. vitamin C

Answers

It’s not b because vinegar is no less than 4%. Most likely it’s C but I’m not sure if you do choose C let me know if I’m wrong or right. Good luck !


A piece of dry ice at -76°C begins to sublimate (solid to
gas) when placed at the counter at room temperature. How
many bars are in the final phase energy (Eph)?

Answers

Answer:

D

Explanation:

4 bars

HELP 20 POINTS

What is the frequency of an Electromagnetic wave has with wavelength 2.94 x 10^-8 cm?

Answers

The answer is 30.84

which force does the truck use to move the car with it A.push B.pull C.gravity D.Friction

Answers

it is push i think to move the car

Answer:

Either A. Push or B.Pull because the truck is either pushing or pulling the car to move it. So it depends on if it's pushing or pulling the car.

Explanation:

Solve for x in the following equation?

v=w/x

Answers

Answer:

x = w/v

General Formulas and Concepts:

Pre-Algebra

Equality Properties

Explanation:

Step 1: Define

v = w/x

Step 2: Solve for x

Multiply x on both sides:                    xv = wDivide v on both sides:                      x = w/v

PLEASE HELP WILL GIVE BRAINLIEST

Answers

Answer:

Coefficients represents no of moles while subscripts represent no of atoms.

Answer:

Coefficients came before formula . Example = 4CO means there are 4 molecules of carbonmonooxide.

Subscripts came after and below the formula . Example = Oxygen gas in which 2 is a subscript which means there are 2 atoms of Oxygen in 1 molecule of Oxygen i.e. oxygen gas

Look at the following chemical equation.

10Ag + S = 8Ag S

What is true about this chemical equation? (Hint: The reactant is the substance at the start of a chemical reaction.

The product is the substance at the end of the chemical reaction.

A.It is unbalanced because the number of reactants is less than the number of products.

IB.t is balanced because the products contain the same number of sulfur (S) atoms as the reactants.

C.It is balanced because the mass of the reactants is equal to the mass of the products.

D.It is unbalanced because the products contain fewer silver (Ag) atoms than the reactants.

Answers

Answer: I think it is D

Explanation:

A 700 mL sample of gas at STP is compressed to 300 mL, and the
temperature is raised to 100.C. What is the new pressure of the gas in atm?

Answers

Answer:

P₂ =  3.19 atm

Explanation:

Given data:

Initial volume = 700 mL

Initial pressure = 1 atm

Initial temperature = 273K

Final temperature =100°C (100+273= 373 K)

Final volume = 300 mL

Final pressure = ?

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

P₂ = P₁V₁ T₂/ T₁ V₂  

P₂ = 1 atm × 700 mL × 373K / 273 K ×300 mL  

P₂ = 261100 atm .mL. K   /81900 K .mL

P₂ =  3.19 atm

How does Gas Trapping bottles Monitor Volcanos?

( put in your own words don’t look up on internet )
I will give brainlst If you answer correctly.

Answers

Answer: the pressure releases gas. The two most abundant gases are sulfur dioxide and carbon dioxide, and if levels of these gases increase,

Explanation:

Which force acts on falling objects to oppose gravity?
pull
terminal velocity
air resistance
acceleration

Answers

The answer is pull your welcome

Answer:pull

Explanation:

Your skin is an important organ and has several functions. All of the functions below are performed by the skin EXCEPT
A)
makes vitamin D.
B
prevents-dehydration:
C)
maintains body temperature.
D)
works with bones to help you move.

Answers

Answer:D

Explanation:

Your skin makes vitamin D

Your skin prevents dehydration

And your skin maintains body temperature. So you are left with D

Answer:

The correct option is D.

works with bones to help you move

Explanation:

Skin is the outer layer of the body and it is the body's largest organ.

It protect the body from heat and other harmful substances.

It is comprises of three layers;

The Epidermis which is the outer layer.

The dermis which is a fibrous later that protect the Epidermis.

The subcutis is the subcutaneous layer that is beneath the dermis.

Function of the skin.

1. It's regulate body temperature

2. It's protect the body from heat and pathogenic entry.

3. It produces vitamin D

4. The skin allow sensations or feelings of touch, heat, and cold.

Therefore;

works with bones to help you move is wrong because it is the muscle that work with the bone.

A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ . Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.

Answers

1. A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond.

1. A: Unpaired, and homolysis

2. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals.

2. A: Resonance, and more

3. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ .

3. A: Initiator

4. Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.

4. A: Allylic substitution by radical

if you aint stephanie dont anwer​

Answers

lol I just did though :)

Answer:

wsp

Explanation:

true or false A force can change the shape of an object.

Answers

Answer:

True

Explanation:

When a force acts on an object, the object may change shape by bending, stretching or compressing - or a combination of all three shape changes.

A precipitate of lead chloride is formed when silver chloride is dissolved in a saturated solution of lead chloride due to g

Answers

Answer:

Due to "Common ion effect".

Explanation:

Lead chloride and Silver chloride have an ion in common which is Cl-, when these two solutions are dissolved, more chloride reacts with lead which shifts equilibrium position to the right hence precipitating out.

Step 1: (slow)
Step 2: NO3(g) + CO(g) + NO2(g) + CO2(g) (fast)
Overall: NO2(g) + CO(g) + NO(g) + CO2(g)
A two-step reaction mechanism is proposed for a gas-phase reaction, as represented above. Which of the following correctly identifies both the chemical equation for step 1 and the rate law for the overall reaction?
A) The chemical equation for step 1 is 2 NO2(g) → NO(g) + NO3(g), and the rate law is rate = (NO,].
B) The chemical equation for step 1 is NO2(g) + CO(g) + NO(g) + CO2(g), and the rate law is rate = [NO2][CO).
C) The chemical equation for step 1 is NO3(g) + 2 CO(g) + NO(g) + 2 CO2(g), and the rate law is rate = [NO2][CO).
D) The chemical equation for step 1 is NO3(g) + NO2(g) + 2 CO(g) + NO(g) + NO2(g) + 2 CO2(g), and the rate law is rate = [NO3][NO2][CO]".

Answers

Answer:

The chemical equation for step 1 is 2 NO2(g) → NO(g) + NO3(g), and the rate law is rate = k[NO2]^2

Explanation:

We know that the rate determining step is the slowest step in a sequence of non elementary reactions.

As we can see, the first reaction is slow so it is the rate determining step. From here we obtain the rate equation.

Also, the specie NO3 is absent in the overall reaction equation indicating that it is merely an intermediate produced in step 1 and used up in step 2.

The chemical equation for step 1 is [tex]2 NO_2(g) \rightarrow NO(g) + NO_3(g)[/tex], and the rate law is [tex]rate = k[NO_2]^{2}[/tex].

The rate -determining step is the slowest step in a sequence of non -elementary reactions.  The first reaction is slow so it is the rate determining step. From here we obtain the rate law.

Also, the specie [tex]NO_3[/tex]  is absent in the overall reaction equation indicating that it is merely an intermediate produced in step 1 and used up in step 2.

So, the chemical equation for step 1 is [tex]2 NO_2(g) \rightarrow NO(g) + NO_3(g)[/tex], and the rate law is [tex]rate = k[NO_2]^{2}[/tex].

To know more about:-

https://brainly.com/question/4222261

NEED HELP PLZ ASAP!!!!!

Answers

you need to give more info

someone please help me, the picture is shown above !

Answers

The quality of being easily dissolved in liquid.

Hope this help and Happy holidays
I can’t really see the question and answer choices

What is a "mole" in chemistry?

Answers

Answer:

Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other

Answer:

Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.

Explanation:

A typical home instant pot has an internal volume of 6.5 Liters. If the steam inside an instant pot with an internal pressure of 191.0 kPa and a temperature of 750.0 K was released into the atmosphere at 101.3 kPa and 298K, what volume with the steam occupy in the atmosphere?

Answers

Answer: V2 = 4.8696 L is the volume occupied by the steam in the atmosphere

We can use the combined gas law to solve this problem.

Combined gas law: P1 V1 / T1 = P2 V2 / T2

(191.0 kPa)(6.5 L) / (750.0 K) = (101.3 kPa)(V2) / (298 K)

Now we solve for V2;

1241.5 / 750 = 101.3 / 298

Now we cross-multiply;

369967 = 75975x

Divide by 75975 on each side;

369967 / 75975 = 75975x / 75975

Round our answer to sig figs;

x (aka V2) = 4.8696 L is the volume occupied by the steam in the atmosphere
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