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.

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Related Questions

Cu2O + C->
Cu + CO2
Balance the above reaction by writing in the correct coefficient.

Answers

Answer:

2 Cu2O + C = 4 Cu + CO2

Explanation:

CU2O has 2 coefficient

C has 1 coefficient

Cu has 4 coefficient

CO2 has 1 coefficient

Balance Equation 2 Cu2O + C = 4 Cu + CO2

Answer:

2CU2O + C -----> 2Cu + CO2

Explanation:

2 is added in reactants to balance oxygen O on both sides and 2 before Cu is added in products to balance Cu on both sides.

Mammals and plants do not belong in the same domain.

Fact:

Evidence:

Answers

False

Fact: Mammals and plants belong to the same domain, the Eukarya domain.

Evidence :All the organisms that possess a eukaryotic cell, plants, animals, protists, and fungi are in the Eukarya domain.

Hi pls help with these questions. Will give brainliest for correct answer :)

Answers

Answer:

4

Explanation:

because those to elements link together creating amazing fractions

A thermochemical equation indicates the absorption or release of heat in addition to the reactants and products involved in the chemical reaction. The amount of energy available for conversion into heat is represented by a triangle H does this term stand for?

Answers

Answer:

A. Enthalpy of the reaction

Explanation:

A Thermochemical equation is a balanced stoichiometric chemical equation that indicates the absorption or release of heat in addition to the reactants and products involved in the chemical reaction. The amount of energy available for conversion into heat is represented by ΔH, a this term which stands for the enthalpy change, ΔH.

The Enthalpy of Reaction or Heat of Reaction is the amount of energy in the form of heat transferred during a chemical reaction that occurs at a constant pressure. It is useful for calculating the amount of energy per mole either released or produced in a reaction, therefore is unit is kJ/mol.

In a reaction where energy is absorbed by the reactants during the formation of products, ΔH is positive. On the other hand, in a reaction where energy is released by the reactants during the formation of products, ΔH is negative.

The enthalpy change, ΔH of reactions are determined experimentally under standard conditions of 1 atm and 25 °C (298.15K). Enthalpy can be measured experimentally through the use of a calorimeter. A calorimeter is an isolated system which has a constant pressure and in which heat loss to the surroundings is minimal.

Please help fast, I will give brainliest.

Answers

Answer:

B

Explanation:

B is the answer if I’m not wrong

Uniformitarianism is the idea that

Answers

Answer:

Uniformitarianism is the idea that the natural processes operating today are the same as the natural processes that operated in the past

Which of the following has a negative charge?

neutrons
electrons
nucleus
protons

Answers

Answer:

electrons have a negative charge

Explanation:

Answer:

Electrons

Explanation:

what is the meaning of resolution in science?
help me please

100% verified brainly answers to give me please.​

Answers

Answer:

Resolution is the ability to distinguish two objects from each other. Light microscopy has limits to both its resolution and its magnification.

83.0 g Lithium Cyanide (LiCN)
Can someone please convert this to molar mass and moles for 100point?
it's not a scam like I really need this done before class is done

Answers

Molar mass:-

[tex]\\ \sf\longmapsto LiCN[/tex]

[tex]\\ \sf\longmapsto 7u+12u+14u[/tex]

[tex]\\ \sf\longmapsto 21u+12u[/tex]

[tex]\\ \sf\longmapsto 33u[/tex]

[tex]\\ \sf\longmapsto 33g/mol[/tex]

Given mass=83g

No of moles=Given Mass/Molar mass

[tex]\\ \sf\longmapsto \dfrac{83}{33}[/tex]

[tex]\\ \sf\longmapsto 2.5mol[/tex]

How is the rotation of the Sun different from the rotation of Earth?
OThe parts of the Sun rotate at different speeds and the parts of Earth rotate at the same speed.
O The Sun's equator rotates faster than its poles and Earth's equator rotates slower than its poles.
O The Sun's poles rotate faster than its equator and Earth's poles rotate slower than its equator.
O The parts of the Sun rotate in different directions and the parts of Earth all rotate in the same direction

Answers

Answer:

The Sun's equator rotates faster than it's poles and Earth's equator rotates slower than it's poles.

Explanation:

Two forms of energy found in all systems are kinetic energy and

Answers

Answer:

Potential energy

Explanation:

You start with 2.5g of magnesium and add it to 400mL of CO2 at 23 o C and 1atm. How many grams of magnesium oxide will be formed?

Answers

Answer:

0.664 g are formed by the reaction.

Explanation:

First of all, we determine the reaction:

Mg + CO₂  →  MgO  + CO

We need to determine the moles of the CO₂ by the Ideal Gases Law.

We convert to L, the volume → 400 mL = 0.4L

T° → 23°C + 273 = 296K

P . V = n . R .T

n = P . V / R .T

n = (1 atm . 0.4L) / (0.082 . 296K) → 0.0165 moles

Moles of Mg → 2.5 g . 1mol / 24.3g = 0.103 moles

As ratio is 1:1, CO₂ is the limiting reactant.

For 1 mol of Mg, we need 1 mol of gas

Then, for 0.103 moles of Mg, we need 0.103 moles of gas, but we only have 0.0165 moles.

If we see the product side, ratio is also 1:1

0.0165 moles of CO₂ must produce 0.0165 moles of MgO.

We convert the moles to mass → 0.0165 mol . 40.3 g /1mol = 0.664 g

Given the following equation: Na2O + H20 - 2 NaOH
How many grams of Na20 are required to produce 1.60 x 102
grams of NaOH?
g

Answers

Answer:

124g  

Explanation:

The concept stoichiometry is used here to determine the mass of Na₂O. The grams of Na₂O required to produce 1.60 x 10² grams of NaOH is  124 g.

What is Stoichiometry?

The stoichiometry is an important concept of chemistry which help us to use the balanced chemical equation to calculate the amounts of reactants and products. The stoichiometric coefficient is the number of molecules that can participate in the reaction.

The balanced equation is:

Na₂O + H₂O → 2NaOH

1 mole of Na₂O is required to react with 1 mole of  H₂O to give 2 moles of NaOH.

62 g of Na₂O produces 80 g of NaOH.

1 g of NaOH is produced from 62/80 g of Na₂O .

1.6 × 10² g of NaOH will require 62 × 1.6 × 10² g / 80 g of Na₂O = 124 g Na₂O

Thus the grams of Na₂O required to produce 1.6 × 10² g of NaOH is 124 g.

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The Statue of Liberty changing from Copper to Green is an example of...
Group of answer choices

A: Temperature Change

B: Gas Formation

C: Color Change

D: Precipitate

Answers

Answer:

answering this for points! Sorry! but its probably A OR C

Explanation:

can someone help w/ chem plzz

Answers

Answer:

my answer I think is tetrahedral

define satt and give an example?​

Answers

Answer:

Heyy..Here is your answer..

Satt is the German word for full and it most likely comes from the same Latin word that saturated.

Hope it helps..!!

why an aspirin tablet works faster if it is crushed rather than swallowed whole?​

Answers

Answer: because the tablet is already crushed and is easy for the organism to absorb instead of having to break it down

Explanation:

A sample of an oxide of nitrogen is found to contain 30.4% nitrogen. What is its empirical formula?

Answers

Answer:

If nitrogen = 30.4% then oxygen = 100-30.4 = 69.6%

divide each % value by atomic mass

N = 30.4/14 = 2.17

O = 69.6/16 = 4.35

Divide each y smaller:

N = 2.17/2.17 = 1

O = 4.35/2.17 = 2

Explanation:

"The empirical Formula will be [tex]NO_{2}[/tex]."

What is empirical formula?

In chemistry, an empirical formula is the simplest thought of the entire number quantity of atoms in a molecule.

It is given that N = 30.4%.

The % of O can be determined as: 100-30.4%= 69.65.

Now, after dividing % value with atomic mass, we get.

Mass of  N= 14 and Mass of O = 16.

N= 30.4/14= 2.17

O = 69.6/ 16= 4.35

It can be seen that N has less number as compared to O . So, divide each with 2.17.

N= 2.17/2.17 = 1

O = 4.35/2.17=2

So the empirical formula will be [tex]NO_{2}[/tex].

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Can anyone tell me 5 reactions of metals with nonmetals?​

Answers

non-Metals:

Nitrogen.

Oxygen.

Helium.

Sulfur.

Chlorine.

Explanation/Answer:

Metal atoms have only a few electrons in their outer shell whereas non-metal atoms have lots of electrons in their outer shell. This means that metals tend to react with non-metals. When a metal reacts with a non-metal, electrons transfer from the metal to the non-metal.

HOPE I HELPED!!

The freezing point of a substance is the
at
which it freezes.

Answers

Answer:

reff lagay mo yung ilalagay mo

Answer:

Freezing point is the temperature at which a liquid becomes a solid at normal atmospheric pressure. Alternatively, a melting point is the temperature at which a solid becomes a liquid at normal atmospheric pressure.

Are physical characteristics of an organism not genetically passed down?

Answers

That is false. Physical characteristics of an organism can be genetically passed down.

—Evidence—

An inherited trait is a feature or characteristic of an organism that has been passed on to it in its genes. This transmission of parental traits to their offspring always follows certain principles or laws. The study of how inherited traits are passed on is called genetics.

In an ecosystem, the  physical characteristics of an organism are genetically passed down  from one generation to another.

What is an ecosystem?

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

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How many atoms are in 2.54 mole O?

Answers

Answer:  1.505 * 10^24 atoms

========================================================

Work Shown:

1 mole = 6.02 * 10^23 atoms

2.5*(1 mole) = 2.5*(6.02 * 10^23 atoms)

2.5 moles = (2.5*6.02) * 10^23 atoms

2.5 moles = (15.05) * 10^23 atoms

2.5 moles = (1.505 * 10^1) * 10^23 atoms

2.5 moles = 1.505 * (10^1*10^23) atoms

2.5 moles = 1.505 * 10^(1+23) atoms

2.5 moles = 1.505 * 10^24 atoms

This is true for any element. This value is an approximation since there are roughly 6.02 * 10^23 atoms in 1 mole of any element.

Since the speed of light, “c”, is 0.3% slower in air than it is in outer space, how does that affect the observed wavelengths?

Answers

Answer:

....interesting

what is a method to isolate insoluble salts after a neutralisation reaction

Answers

Answer:

multiply

Explanation:

multiplacation

Collision of which two types of plates create the deepest earthquakes? Why do you think this is?

Answers

Answer:

The collision of oceanic plates and any other plates in which the oceanic plate slides beneath the other plate creates the biggest earth quakes. Most of these earth quakes occur beneath the sea or oceans and can cause volcanic eruptions as well. Tsunami is another oceanic event that occurs due to earth quakes occurring due to shifting of plates beneath the sea.

How does a sugar solution become rock candy?

Answers

Answer:

Explanation:

A supersaturated solution is unstable—it contains more solute (in this case, sugar) than can stay in solution—so as the temperature decreases, the sugar comes out of the solution, forming crystals. The lower the temperature, the more molecules join the sugar crystals, and that is how rock candy is created.

If I initially have a gas at a pressure of 12 kPa, a volume of 23 liters, and a temperature of 200 K, and then I raise the pressure to 14 kPa and increase the temperature to 300 K, what is the new volume of the gas?

Answers

Answer:

The new volume of gas would be 30 L.

Explanation:

This is an example of a Combined Gas Laws problem.

how do compaction and cementation cause sediments and form sedimentary rock

Answers

Answer:

Dissolved minerals in the ground water precipitate (crystallize) from water in the pore spaces forming mineral crusts on the sedimentary grains, gradually cementing the sediments, thus forming a rock

Explanation:

calculate the volume occupied by 10g of propane gas, under normal conditions of temperature and pressure

Answers

Answer:

5.5 L

Explanation:

First we convert 10 g of propane gas (C₃H₈) to moles, using its molar mass:

10 g ÷ 44 g/mol = 0.23 mol

Then we use the PV=nRT formula, where:

P = 1 atm & T = 293 K (This are normal conditions of T and P)n = 0.23 molR = 0.082 atm·L·mol⁻¹·K⁻¹V = ?

1 atm * V = 0.23 mol * 0.082 atm·L·mol⁻¹·K⁻¹ * 293 K

V = 5.5 L

what is the defination of epsom salt?

Answers

crystals of hydrated magnesium sulfate used as a purgative or for other medicinal use


It on googIe
Hope that helps
epsom salt is a crystals of hydrated magnesium sulphate used as a purgative or for other medicinal use.

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