In NMR: The size of coupling constants (J values) depend on three factors:
a. Through bond distance between the protons.
b. Angle between the two C-H bonds.
c. Electronegative substituents.
1. True
2. False
Answer:
True
It is true that he size of coupling constants (J values) depend on three factors:
a. Through bond distance between the protons.
b. Angle between the two C-H bonds.
c. Electronegative substituents.
Explanation:
With the increase in the valence angle the coupling constant reduces. The distance between the carbon atoms also influence coupling constant. With increase in bond length, the coupling constant decreases. Also the more an atom is electronegative, the lesser is the coupling constant
Thus, it is true that he size of coupling constants (J values) depend on three factors:
a. Through bond distance between the protons.
b. Angle between the two C-H bonds.
c. Electronegative substituents.
When the temperature of a reaction is raised from 278 K to 300 K, the reaction rate increases by a factor of 17. Determine the activation energy, Ea, of the reaction. R = 8.314 J/mol.K
Answer: The activation energy, Ea, of the reaction is 89195 Joules
Explanation:
The effect of temperature on rate constant is given by Arrhenius equation:
[tex]ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}][/tex]
where
[tex]k_2[/tex] = rate constant at temperature [tex]T_2[/tex]
[tex]k_1[/tex] = rate constant at temperature [tex]T_1[/tex]
[tex]E_a[/tex]= activation energy
R= gas constant
[tex]T[/tex] = temperature
[tex]ln \frac{17k_1}{k_{1}} = \frac{-E_{a}}{8.314}[\frac{1}{300} - \frac{1}{278}][/tex]
[tex]2.83=\frac{-E_{a}}{8.314}[\frac{1}{300} - \frac{1}{278}][/tex]
[tex]E_a=89195J[/tex]
The activation energy, Ea, of the reaction is 89195 Joules
please help me! This is due by tomorrow!
Answer:d
Explanation:Since the earth would be closer to the sun the ozone layer would not be able to handle the more powerful ultra violet rays making the earth to hot.
Vitamin C is a covalent compound with the molecular
formula C6H8O6. The recommended daily dietary
allowance of vitamin C for children aged 4-8 years is
0.000142mol. What is the mass of this allowance in grams?
The mass allowance of Vitamin C for children aged 4-8 years is equal to 0.025 grams.
What is a mole?A mole can be defined as a standard unit that can be utilized to evaluate the number of entities such as atoms, molecules, ions, or other particular particles in a particular amount of the substance.
The number of elementary entities present in one mole of any chemical substance was found to be equal to 6.023 × 10²³ which is also known as the Avogadro number.
Given, the number of moles of vitamin C = 0.000142 moles
Given, the molecular formula of Vitamin C is C₆H₈O₆.
The mass of one mole of C₆H₈O₆ = 176 g
One mole of Vitamin C has mass = 176 g
0.000142 mol of Vitamin C has mass = 0.000142×176 = 0.025 g
Therefore, the mass of 0.000142 mol of Vitamin C is 0.025 g.
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which element has 51 protons in its nucleus?
Answer:
Antimony
Explanation:
Protons-51
Neutrons-71
Electrons-51
What three biotechnologies do you think are the most important???
Answer:
Vaccines. Vaccines are chemicals that stimulate the body's immune system to better fight pathogens when they attack the body. ...
Antibiotics. ...
Pest Resistant Crops. ...
Plant and Animal Breeding. ...
Biocatalysts. ...
Fermentation. ...
Microorganisms. ...
Bioremediation.
Explanation:
Draw a mechanism for the reaction of water with formic acid. In the box to the left, draw any necessary curved arrows. Show the products of the reaction in the box to the right. Include any nonzero formal charges and all lone pairs of electrons. Finally, indicate which side of the reaction is favored at equilibrium.
Answer:
See explanation
Explanation:
When water reacts with formic acid, The following equilibrium is set up;
HCOOH(aq) + H20(l) ⇄ HCOO-(aq) + H30+(aq)
This is because, the water abstracts a proton from formic acid to form its conjugate base, formate ion.
At equilibrium, the forward is favored.
What is the percent oxygen in Rb2Cr2O7
Answer:
28.9452
Explanation:
Answer:
28.9452%
Explanation:
Rb-44.1781
Cr-26.8767
O-28.9452
When a liquid is at its boiling point, the vapor pressure of the liquid
is less than the external pressure on the liquid.
is equal to the external pressure on the liquid.
is greater than the external pressure on the liquid.
can be either less or greater than the external pressure on the liquid.
Answer:
=external pressure on liquid
la densidad de un aceite liviano para vehiculo es 0.87g/cm3 calcules su volumen especifico y peso especifico
Answer:
Pe = 8700 N/m³
Vesp = 1,15 cm³/g
Explanation:
Ya que conocemos el valor de la densidad de este aceite, es muy sencillo calcular tanto volumen como peso específico.
En el caso de volumen específico, esta se refiere al cociente del volumen de un líquido con su masa respectiva. En otras palabras, es el inverso de la densidad, por tanto usamos la siguiente expresión para el volumen específico:
Vesp = 1/d
Vesp = 1 / 0,87
Vesp = 1,15 cm³/gPara el caso del peso específico, se calcula como el cociente de la masa del líquido y su volumen que ocupa. Sin embargo no conocemos ninguno de esos dos datos, por lo que para calcular el peso específico solo basta multiplicar este valor por la aceleración de gravedad, que vamos a asumir para este problema que es 10 m/s². Y ademas cambiaremos las unidades de densidad de g/cm³ a kg/m³. Esto es porque las unidades de peso específico son N/m³ y los newton (N) son kg m/s².
d = 0,87 g/cm³ * (1 kg/1000g) * (100 cm/1m)³ = 870 kg/m³
Pe = 870 kg/m³ * 10 m/s²
Pe = 8700 N/m³ESpero te sirva.
If a country has a large amount of children born, but most do not live past 5, the population
pyramid would be described as:
Expansive
Constrictive
Stationary
Answer:
Constrictive,
Explanation:
Constrictive population pyramid displays lower percentages of younger people
Also what happens if you decrease NOCL
Answer:
el que paso del one jhaulio
Explanation:
What does the pH of a solution represent?
A. The pH indicates how acidic or basíc a solution is,
B. The pH represents the partial pressure of hydrogen gas.
O.C. The pH tells how quickly a reaction reaches equilibrium
D. The pH is an indicator of the salt content of a solution
Answer:
a
Explanation:
5. The heat of fusion of lead is 25 J/g and its melting point is 601 K. How much heat is given off as 3.0 g
of liquid lead solidifies at 601 K?
Answer:
the heat given off is 75 J.
Explanation:
Given;
latent heat of fusion of lead, L= 25 J/g
mass of liquid lead, m = 3.0g
The heat given off is calculated as;
H = Lm
Where;
H is the quantity of heat given off
H = 25 x 3
H = 75 J.
Therefore, the heat given off is 75 J.
Propane can be turned into hydrogen by the two-step reforming process. In the first step, propane and water react to form carbon monoxide and hydrogen: (g)(g)(g)(g) In the second step, carbon monoxide and water react to form hydrogen and carbon dioxide: (g)(g)(g)(g) Write the net chemical equation for the production of hydrogen from propane and water. Be sure your equation is balanced.
Answer:
C₃H₈(g) + 6 H₂O(g) ⇒ + 10 H₂(g) + 3 CO₂(g)
Explanation:
Propane can be turned into hydrogen by the two-step reforming process.
In the first step, propane and water react to form carbon monoxide and hydrogen. The balanced chemical equation is:
C₃H₈(g) + 3 H₂O(g) ⇒ 3 CO(g) + 7 H₂(g)
In the second step, carbon monoxide and water react to form hydrogen and carbon dioxide. The balanced chemical equation is:
CO(g) + H₂O(g) ⇒ H₂(g) + CO₂(g)
In order to get the net chemical equation for the overall process, we have to multiply the second step by 3 and add it to the first step. Then, we cancel what is repeated.
C₃H₈(g) + 3 H₂O(g) + 3 CO(g) + 3 H₂O(g) ⇒ 3 CO(g) + 7 H₂(g) + 3 H₂(g) + 3 CO₂(g)
C₃H₈(g) + 6 H₂O(g) ⇒ + 10 H₂(g) + 3 CO₂(g)
Unit cells provide the simplest repeating structures of a crystal. This means a unit cell must contain an integer multiple of the empirical formula.
a. True
b. False
Answer:
True
Explanation:
The unit cell is the smallest group of atoms which has the overall symmetry of a crystal, and from which the entire lattice can be built up by repetition in three dimensions (Oxford dictionary).
The number of atoms in a unit cell of a crystal structure must be equal to or a multiple of the number of atoms in the empirical formula of the compound. In other words, the unit cell should contain the formula unit of the compound.
Helppp Convert 240 seconds into minutes.
Answer:
240/60 .minute
plz make me brainliest
5. Calcium carbide (CaC2) reacts with water, producing acetylene (C2H2): CaC2 + 2H2O -> Ca(OH)2 + C2H2
Production of 13g of C2H2 requires __________ g of H2O. a. 4.5 b. 9.0
c. 18 d. 4.8 x 102 e. 4.8 x 10-2
Answer: c
Explanation:
18
Answer:
17.99 g H2O
Explanation:
13 g C2H2(1 mol C2H2/26.04 g C2H2)(2 mol H2O/1 mol C2H2)(18.02 g H2O/1 mol H2O) = 17.99 g H2O used up
I NEED HELP ASAP! IF I FAIL THIS IMMA GET KICKED OFF THE VOLLEYBALL TEAM!!!!!! PLS TELL ME IS THIS IS CORRECT the picture is above! pls help!
Answer:
The image appears to have some words cropped out. Nonetheless, "receptor" would seem to be the most appropriate term here.
C3H8 (g)+ 502 (g) 3CO2 (g) + 4 H2O (g) + 531 kcal
Answer:
Exotérmica.
Explanation:
¡Hola!
En este caso, dado que la mayoría de reacciones de combustión son exotérmicas, al generar calor en los productos, es posible inferir que esta reacción, referida a la combustion de metano es exotérmica debido a lo anteriormente mencionado, ya que el término de energía de reacción, 531 kcal, está al lado de los productos, lo que quiere decir que es energía generada.
¡Saludos!
Atoms of which of the following elements are largest?
A:
Na
OOOO
Answer:
yes answer os Na because it's electronic configuration is 1s^2,2s^2,2p^6,3s^1
Aqueous hydrochloric acid HCl will react with solid sodium hydroxide NaOH to produce aqueous sodium chloride NaCl and liquid water H2O. Suppose 0.365 g of hydrochloric acid is mixed with 0.18 g of sodium hydroxide. Calculate the maximum mass of sodium chloride that could be produced by the chemical reaction. Round your answer to 2 significant digits.
Answer:
0.26g of NaCl is the maximum mass that could be produced
Explanation:
Based on the reaction:
HCl + NaOH → NaCl + H₂O
Where 1 mol of HCl reacts per mol of NaOH to produce 1 mol of NaCl
To solve this question we need to find limiting reactant. The moles of limiting reactant = Moles of NaCl produced:
Moles HCl -Molar mass: 36.46g/mol-:
0.365g HCl * (1mol / 36.46g) = 0.010 moles HCl
Moles NaOH -Molar mass: 40g/mol-:
0.18g NaOH * (1mol / 40g) = 0.0045 moles NaOH
As the reaction is 1:1 and moles NaOH < moles HCl, limiting reactant is NaOH and maximum moles produced of NaCl are 0.0045 moles.
The mass of NaCl is:
Mass NaCl -Molar mass: 58.44g/mol-:
0.0045 moles * (58.44g/mol) =
0.26g of NaCl is the maximum mass that could be producedYou are given a sample of several compounds to separate by paper chromatography. You draw a pencil line exactly 1.00 cm from the bottom of the paper, and place a spot of sample on it. You dry the sample, then develop it in a solvent. When the chromatogram is taken out of the solvent, the paper is wet up to 9.17 cm from the bottom of the sheet. The compound you are interested in shows up as a spot 7.57 cm from the bottom of the paper. Calculate the following:
a. How far did the compound move?
b. In the same time, how far did the solvent move?
c. What is the Rf factor for the compound?
Answer:
a. 6.57 cm
b. 8.17 cm
c. 0.80
Explanation:
a. The compound moved from where it was first placed, to a spot 7.57 cm from the bottom of the paper, in other words:
7.57 cm - 1.00 cm = 6.57 cmb. A similar method is made for the solvent:
9.17 cm - 1.00 cm = 8.17 cmc. The Rf of the factor is equal to the distance that the compound moved divided by the distance the solvent moved:
6.57 cm / 8.17 cm = 0.80The bond enthalpy of the Br–Cl bond is equal to ΔH°rxn for the following reaction. BrCl(g) → Br(g) + Cl(g) Using the following data, what is the bond enthalpy of the Br–Cl bond?
a. Br2(l) → Br2(g) ΔH°rxn = 30.91 kJ/mol
b. Br2(g) → 2Br(g) ΔH°rxn = 192.9 kJ/mol
c. Cl2(g) → 2Cl(g) ΔH°rxn = 243.4 kJ/mol
d. Br2(l) + Cl2(g) → 2BrCl(g) ΔH°rxn = 29.2 kJ/mol
Answer:
a. Br2 (l) → Br2(g) ΔH°rxn = 30.91 kJ/mol
Explanation:
Bond enthalpy is the energy which is required to break 1 mol of of bonds in gaseous covalent molecules. Bond breaking process can be endothermic or exothermic depending on the molecules association. The process needs to be performed in chemical laboratory under standard conditions.
A hypothetical AX type of ceramic material is known to have a density of 3.15 g/cm3 and a unit cell of cubic symmetry with a cell edge length of 0.41 nm. The atomic weights of the A and X elements are 90.5 and 37.3 g/mol, respectively. On the basis of this information, which one of the following crystal structures is possible for this material?
a. Sodium chloride
b. Cesium chloride
c. Zinc blende
Answer:
b.
Explanation:
From the given information:
[tex]p = \dfrac{zM}{N_oa^3}[/tex]
where;
a = 0.41 nm = [tex]4.1 \times 10^{-8} \ cm[/tex]
M = 90.5 + 37.3 = 127.8 g/mol
[tex]N_o = 6.023 \times 10 ^{23}[/tex]
p = 3.15 g/cm³
∴
[tex]3.15 = \dfrac{z \times 127.8}{(6.02 \times 10^{23}) \times (4.1 \times 10^{-8} )^3}[/tex]
Z = 1
Thus, the ceramic material has a simple cubic crystal system and the crystal structure is possible to be Cesium chloride.
Name each of the following organic molecules. 
What organelle(s) act(s) as "the boss" inside a cell? A.The alveoli B. The mitochondria C. The nucleus D. The lysosomes
The organelle(s) that act(s) as "the boss" inside a cell is The nucleus.
What is cell in the nucleus?Nucleus is the center most part of the cell that contains all the chromosomes and that contains all the genetic information.
The nucleus is a double-membraned organelle that contains the genetic material and other instructions required for cellular processes. It is exclusively found in eukaryotic cells and is also one of the largest organelles.
The nucleus contains nearly all of the cell's DNA, surrounded by a network of fibrous intermediate filaments and enveloped in a double membrane called the nuclear envelope. The nuclear envelope separates the fluid inside the nucleus, called the nucleoplasm, from the rest of the cell.
Therefore, The organelle(s) that act(s) as "the boss" inside a cell is The nucleus.
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If gold is selling presently for $1000.00/oz how much would 1 cubic inch of gold be worth?
Note: 1 inch= 2.54 cm; 1 oz. =28.3 g Density of gold: 19.3 g/cm^3
Answer:
$89.69
Explanation:
$1000 = 1 oz = 28.3g
volume = mass/density
volume = 28.3/19.3 = 1.47cm³
1 inch= 2.54 cm
1 cubic inch = (2.54)³ = 16.39 cm³
16.39/1.47 = 11.15 cubic inch
11.15 cubic inch = $1000
1 cubic inch = 1000/11.15 = $89.69
Find odd one out.
H2SO4 , HCL, NaOH, HNO3
Answer:NaOH
Explanation:all are acids except NaOH
Answer:
it is NaOH
Explanation:
Because NaOH is base, while the others are acid
The formation of ethyl alcohol (C2H5OH) by the fermentation of glucose (C6H12O6) may be represent by the following: C6H12O6 --> 2 C2H5OH 2 CO2 If a particular glucose fermentation process is 70.0% efficient, how many grams of glucose would be required for the production of 51.0 g of ethyl alcohol (C2H5OH)
Answer:
142.5 g
Explanation:
According to the chemical reaction:
C₆H₁₂O₆ --> 2 C₂H₅OH + 2 CO₂
1 mol of glucose (C₆H₁₂O₆) forms 2 moles of ethyl alcohol (C₂H₅OH) and 2 moles of carbon dioxide (CO₂).
We first convert the moles to grams by using the molecular weight (Mw) of each compound:
Mw (C₆H₁₂O₆) = (12 g/mol x 6) + (1 g/mol x 12) + (16 g/mol x 6)= 180 g/mol
1 mol C₆H₁₂O₆ = 180 g/mol x 1 mol = 180 g
Mw(C₂H₅OH) = (12 g/mol x 2) + (1 g/mol x 5) + 16 g/mol + 1 g/mol= 46 g/mol
2 mol C₂H₅OH = 2 mol x 46 g/mol = 92 g
Thus, when the process is 100% efficient, 180 grams of glucose produce 92 grams of ethyl alcohol. To form 51.0 grams of ethyl alcohol, we will need:
51.0 g C₂H₅OH x (180 g C₆H₁₂O₆/92 g C₂H₅OH) = 99.8 g C₆H₁₂O₆
As the process has a lower efficiency (70.0%), we will need more glucose to obtain the required yield. So, we divide the mass of glucose required for a process 100% efficient by the actual efficiency:
mass of glucose required = 99.8 g C₆H₁₂O₆/(70%) = 99.8 g C₆H₁₂O₆ x 100/70 = 142.5 g
Therefore, it would be required 142.5 grams of glucose to obtain 51.0 grams of ethyl alcohol.