Q1.

How many peaks are there in the 13C NMR spectrum of 1,4-dimethylbenzene?


A: 8

B: 4

C: 3

D: 2

Answers

Answer 1

Answer:

there are four peaks in the 13c NMR (B)

Answer 2

To solve this we must be knowing each and every concept related to NMR. Therefore, the correct option is option B among all the given options.

What is NMR?

NMR spectroscopy is a form of spectroscopy that may be used to evaluate the quality or purity of such a sample as well as the molecular weight of a substance.

It really is based on the observation that now the nuclei among most atoms have spin and that all nucleus are electrically charged. NMR spectroscopy relies on the electromagnetic radiation absorption in the radiofrequency range 3kHz-300 GHz. There are four peaks in the 13C NMR  spectrum of 1,4-dimethylbenzene.

It occurs at such a wavelength that corresponds to radio frequencies, and when an electron recovers from such an excited state back ground state, it produces the same frequency radio wave.

Therefore, the correct option is option B.

To know more about NMR, here:

https://brainly.com/question/28484846

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Related Questions

[urgent]

What would the [OH-] of a solution that has a pOH of 2.7 be?

Answers

Answer:

[OH⁻] = 0.002 M

Explanation:

The definition of pOH is similar to the definition of pH:

pOH = -log[OH⁻]

This means that with a given pOH value, the calculation of [OH⁻] is a matter of algebra:

2.7 = -log[OH⁻]-2.7 = log[OH⁻]

To remove the logarithm we increase 10 by the power of the pOH:

[tex]10^{-2.7}[/tex]=[OH⁻]0.002 M = [OH⁻]

The F1-ion is classified as a(n).
and has:
A.anion, 1 valence electron
B.anion, 8 valence electrons
C.cation, 2 valence electrons
D.cation, O valence electrons

Answers

Answer:

B

Explanation:

The [tex]\rm \bold{F^1^-}[/tex] is the fluorine anion with 8 valence electrons. Hence, option B is correct.

An ion is defined as the atom with the change in the valence electrons by the loss or gain of electrons to complete the outer shell.

What type of ion is [tex]\rm F^1^-[/tex]?

The ions with the gain of electrons result in a negative charge and are termed anions. The ions with a loss of electrons have a positive charge and are termed cations.

The F is the halogen atom of group 17 with 7 valence electrons. The ion formed for F requires 1 electron to complete its valence shell.

The ion [tex]\rm F^1^-[/tex] has a negative charge, which denotes it gains an electron and forms anion.

The gain of electrons results in the number of valence electrons being 8.

Thus, [tex]\rm F^1^-[/tex] is the fluorine anion with 8 valence electrons. Hence, option B is correct.

Learn more about ions, here:

https://brainly.com/question/1782326

HELPP!! I REALLY NEED TO BRING UP MY SCIENCE GRADE!!!!
Scientists studied the location of ____ to determine plate boundaries.

Answers

Answer:

Of earthquakes

Explanation:

Earthquake i think...

PLEASE HELPPP ILL GIVE BRAINLIEST!!!!!!!!!!!!!

Answers

veins is the correct answer

Answer:

it travels through the veins

How many electrons are transferred when Be and O bond?
02
0
3
4.

Look at picture
ASAP please will mark as brainlist don’t got much time

Answers

Answer:

2 electron are transferred when Be and O bond formed

Answer:

2 is the answer:)))))))))

Assume that 41.1g of hydrogen peroxide decompose to produce oxygen gas at STP to the following balanced equation:

2H2O2 (l) ---------> 2H2O(l) + O2 (g)

How many Liters of oxygen gas are produced?

Answers

Answer:The hydrogen bond is responsible for many of the anomalous physical and chemical properties of compounds of N, O, and F. In particular, intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides that have much weakerhydrogen bonds

Hydrogen bonding is primarily responsible for the high ______ of water.

When calcium chloride and baking side is mixed, is it an example of chemical or physical change?

Answers

it’s a chemical change

Why does the moon's gravitational pull have more effect on Earth's tides than the sun's gravitational pull?


A. The moon is closer to the Earth than the sun.

B.The moon has more mass than the sun.

C. The moon is more dense than the sun.

D. The moon has a greater diameter than the sun.

Answers

I believe it’s c because if you really read and close read it will make more sense
It’s A. The moon is closer to the earth than the sun

Identify this reaction.
NH3 + H2SO4 → (NH4)2SO4
O decomposition
O synthesis
O double displacement
O single displacement

Answers

Answer: synthesis

Explanation:

Answer:

Synthesis

Explanation:

Two compounds combine to produce one compound

Nitrogen gas is being withdrawn at the rate of 4.5 g/s from a 0.15-m3 cylinder, initially containing the gas at a pressure of 10 bar and 320 K. the cylinder does not conduct heat, nor does its temperature change during the emptying process. What will be the temperature and pressure of the gas in the cylinder after 5 minutes? What will be the rate of change of the gas temperature at this time? Nitrogen can be considered to be an ideal gas with Cp*=30 J/mol.K.

Answers

Answer:

Final temperature = 152.57K,

Pressure = 0.6907 bar.

dT/dt = - 1,151 K/s.

Explanation:

The first thing to do here is to write out the equation for mass balance as given below:

dN/dt = N -------------------------------------------------------------------------------------------(1).

N = P/T, then, substitute the values given in the question into:

d[p/T]/ dt = [- 4.5/28 × 8.314]/0.15 = - 8.9 × 10⁻⁵ bar/K.s.

Thus, there is the need to integrate, Integrate [p/T]f = 10/320 - 8.9 × 10⁻⁵ bar/K.s. ------------------------------------(2).

NB; fT = final temperature, fP = final pressure and iT = initial temperature.

Also, [ fT]³⁰/₈.₃₁₄/ [fP] = [iT]³⁰/₈.₃₁₄/ Pi] = [ 320]³⁰/₈.₃₁₄/ 10.

Therefore, [fT]³⁰/₈.₃₁₄ = 109.52 × 10⁶.

Final temperature=  [fP]³⁰/₈.₃₁₄ × 169.05.

Note that fP/ [fP]³⁰/₈.₃₁₄ × 169.05 = 10/320 - 8.9 × 10⁻⁵.

Therefore, [fP]¹ ⁻ ³⁰/₈.₃₁₄ = 0.7651.

Hence, Final temperature = 152.57K,

Pressure = 0.6907 bar

dT/ dt = N[RT]² / Cv . PV.

R = 30 - 8.314 = 21.86 J/mol K.

Then, the rate of change of the gas temperature at this time = dT/dt = - 1,151 K/s.

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below.

Answers

The question is incomplete, The complete question is;

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. What experimental evidence led to the development of this atomic model from the one before it?

Answer:

A few of the positive particles aimed at a gold foil seemed to bounce back.

Explanation:

This model of the atom was proposed by Ernest Rutherford and was called the planetary model of the atom.

This model is based on an experiment using a gold foil on which alpha particles were focused. Most of the alpha particles passed through the foil. Some of the alpha particles were scattered at large angles and a few seemed to bounce back.

This led to the conclusion that the atom has a massive positive core around which electrons move as planets move around the sun.

Answer:

It is A

Explanation:

I NEED HELP ASAP, If you help me I’ll give you Brainlist [Calorimetry and specific heat lab]
I don’t know how to calculate the error %
The formula is:
%Error = [I Accepted value-Experimental value I / Experimental value] x 100 can someone please PLEASE help me :(

Answers

Answer:

Explanation:

I gave this formula as

What you should get - what you got

---------------------------------------------------   * 100

What you should get

Suppose you are talking about the specific heat of copper and you did a lab and did it fairly well and the specific heat came out to be 0.33

That's what you got, 0.33

What you should get is 0.35 according to the table you've given us.

% error = 0.35 - 0.33

                -------------- * 100

                      0.35

% error = 0.02 * 100/ 0.35

% error = 2/0.35

% error = 5.71

Now here is the really hard part. You have to decide what a positive error is and what a negative error.

A positive error using this formula means you are too low.

A Negative error means that you are too high, just the opposite of what you might think.

Can you show us the experimental value?

So basically, the accepted value would be under the Specific heat capacity of metal (e.g. 0.90, 0.35, 0.44, 0.12).

Your experimental value would be the specific heat capacity that you got from the lab.

You would first substract the experimental value from the accepted value

[tex]accepted \: value - experimental \: value [/tex]

and then you would divide the result by the experimental value

[tex]result \div experimental \: value[/tex]

and then, you would multiply the result of that by a hundred to get your percentage

[tex]result \times 100 = \% \: error[/tex]

//

The image shown is an example.

0.90 is our accepted value.

0.88 is our experimental value.

The overall percentage error I got is %2.27

What is the volume, in liters, of a 0.2 M solution containing 8.5 grams of AgNO3?

Answers

Answer:

0.25L or 250Ml

Explanation:

I am not that good but as far as my calculations this must be the answer

If an atom has 24 p+ and 24e-, what is the atomic number of this element?

Answers

Answer:

24

Explanation:

Because atomic number is the number of protons.

please help which one is it it’s due in 1 hour

Answers

Answer:

carbon monoxide

Explanation:

I'm not sure but I think

Why are red blood cells red

Answers

Red blood cells are red because they contain Haemoglobin

Because of hydrogen bonding,

Select one:
a. liquid water is less dense than ice
b. ice sinks to the bottom of water
c. lakes freeze from the bottom up
d. ice is less dense than liquid water

Answers

Answer:

c. lakes freeze from the botton up

Please help fast, I will give brainliest.

Answers

Answer:

B

Explanation:

B is the answer if I’m not wrong

-
In the reaction: 2X2Y3 + 3Z(QR)4 4X(QR)3 + 3ZY2
What is the charge of the "X" cation needed to form these compounds?

Answers

Answer:

That's simple it's the caca of 54 32 x (5) b ÷ 5683jvl done so your answer is 0

What does the reaction rate measure?

Answers

Answer:

It's C

Explanation:

cuz im goated

What are mineral acids?

Answers

Answer:

mineral acids are obtained from one or more inorganic compounds which is a compound that lacks carbon and hydrogen bonds. Inorganic compound examples include water and carbon dioxide. Something all mineral acids do is form hydrogen ions and the joined together bases when it is dissolved  in water.

Explanation:

What is the total number of atoms in the molecule HNO3?​

Answers

Answer:

We know that, composition of HNO3 is Hydrogen, Nitrogen and oxygen. Total number of atoms = 3+1+1=5 atoms are present in 1 molecule of HNO3.

6) Mr. Collins finally decided to take this seriously and put both hands on the rope and applied a 500 N force to the left,
while Jared and James still struggled with their 300 N force to the right. What is the net force and direction of motion?

Answers

Answer:

I'm pretty sure the net force is 200 N and the direction of motion is left

Explanation:

500 - 300 = 200 and more force is coming from and pulling toward the left.

how many grams of fertilizer , for potassium sulfate are there in 42.3 mole of potassium sulfate? step by step

Answers

Answer:

The mass of 42.3 moles of potassium sulfate is 7,371.1557 grams

Explanation:

Potassium sulfate K₂SO₄ which is also known as sulphate of potash is a water soluble common component of fertilizer

The molar mass of potassium sulfate, M = 174.259 g/mol

The given number of moles of potassium sulfate, n = 42.3 moles

The mass, 'm', of a given number of moles of potassium sulfate, 'n', is given as follows;

m = n × M

Therefore, we have;

The mass, 'm', of 42.3 moles of potassium sulfate is found by plugging in the values for 'M', and 'n', in the above equation as follows;

m = 42.3 moles × 174.259 g/mol = 7,371.1557 grams

The mass of 42.3 moles of potassium sulfate, m = 7,371.1557 grams.

Se queman 87,0 g de butano con oxígeno produciéndose dióxido de carbono y agua. Calcular la masa de oxígeno necesaria y la masa de dióxido de carbono y de agua que se desprenderá

Answers

Answer:

312g O₂ son necesarios, se producen 264g CO₂ y 135g H₂O

Explanation:

La combustión de butano para producir CO₂ y H₂O ocurre así:

C₄H₁₀ + 13/2O₂ → 4CO₂ + 5H₂O

Donde 1 mol de butano reacciona con 13 moles de oxígeno para producir 4 moles de dióxido de carbono y 5 moles de agua.

Para resolver este problema debemos convertir la masa de butano a moles y, usando la reacción balanceada, obtener cuánto se necesita de oxígeno y cuánto se produciría de dióxido de carbono y agua:

Moles butano -Masa molar: 58.12g/mol-:

87.0g * (1mol / 58.12g) = 1.50 moles

Moles y masa de oxígeno necesarias para la reacción -Masa molar: 32g/mol-:

1.50 moles C₄H₁₀ * (13/2 moles O₂ / 1 mol C₄H₁₀) = 9.75 moles * (32g/mol) =

312g O₂ son necesarios

Moles y masa de dióxido de carbono producidas -Masa molar: 44.01g/mol-:

1.50 moles C₄H₁₀ * (4 moles CO₂ / 1 mol C₄H₁₀) = 6 moles * (44.01g/mol) =

264g CO₂ se producen

Moles y masa de agua producidas -Masa molar: 18.015g/mol-:

1.50 moles C₄H₁₀ * (5 moles H₂O / 1 mol C₄H₁₀) = 7.5 moles * (18.015g/mol) =

135g H₂O se producen

What is the volume of a gas at 20°c
If its orginal volume at 60°C
is 300 cm?​

Answers

Explanation:

Using Charles law;

V1/T1 = V2/T2

Convert your temperatures to kelvin;

20+273=298k

60+273=333k

Then put the values the formula stated above

300/333 = V2/298

Make V2 the subject of the formula

V2= (300×298)/333

V2= 89400/333

V2= 268.47cm

When talking about the products of photosynthesis, why is it a HUGE issue when a vast amount of the rainforests is dying along with vast amounts of forests from fires/deforestation? Remember, we know that this hurts the ecosystems of animals living there, but what else does it effect?

Question 5 options:

the creation of oxygen


the creation of too much smoke


the creation of carbon monoxide


the creation of carbon dioxide

Answers

Answer:

the creation of oxygen.

Explanation:

[please answer fast!] If the hydroxide ion concentration is 2x10^-3 M, what is the pH of the solution? Show your working.

Answers

Answer:

pH = 11.30

Explanation:

pH is defined as -log [H⁺]

To find [H⁺] from [OH⁻] -Concentration of hydroxide ion-, we must use the equilibrium of water:

H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)

Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]

[H⁺] = 1x10⁻¹⁴ / [OH⁻]

[H⁺] = 1x10⁻¹⁴ / 2x10⁻³M

[H⁺] = 5x10⁻¹²M

pH = -log (5x10⁻¹²M)

pH = 11.30

HELP ASAP PLS AHHH ty

Answers

Answer: a for the first one , d for the second  one, b for the third one.

Explanation:

Answer:

A: Main sequence star.

B: White Dwarf.

C: Black hole.

Explanation:

Brainliest please.

why are gases able to spread out and fill whatever container they are in

Answers

Answer:

gases are able to spread out and fill whatever container they are in because they do not have. a definite shape their molecules are not tightly packed so they can cover over a vast area like our atmosphere.

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