Write a mechanism for the esterification of propanoic acid with 18O-labeled ethanol. Show clearly the fate of the 18O label. (b) Acid-catalyzed hydrolysis of an unlabeled ester with 18O-labeled water (H218O) leads to incorporation of some 18O into both oxygens of the carboxylic acid product. Explain by a mechanism. (Hint: You must use the fact that all steps in the mechanism are reversible.)
Answers
Answer:
See explanation and images attached
Explanation:
a) In the mechanism for the acid catalysed esterification of propanoic acid using ethanol, we can see that the first step is the protonation of the acid followed by nucleophillic attack of the alcohol. Loss of water and consequent deprotonation regenerates the acid catalyst. We can see the fate of the 18O labelled ethanol in the mechanism shown.
b) In the second mechanism, an unnamed ester is hydrolysed using an acid catalyst. The attack of the acid and subsequent nucleophillic attack of water labelled with 18O leads to the incorporation of this 18O into the product acid as shown in the mechanism attached to this answer.
Related Questions
Calculate the moles of ammonia present in a 5.590 g sample if the molar mass of ammonia is 17.030 g/mol
Answers
Answer:
Number of moles = 0.328 moles.
Explanation:
Given the following data;
Mass = 5.590 g
Molar mass = 17.030 g/mol
To find the number of moles;
[tex] Number \; of \; moles = \frac {mass}{molar mass} [/tex]
Substituting into the equation, we have
[tex] Number \; of \; moles = \frac {5.590}{17.030} [/tex]
Number of moles = 0.328 moles.
A cold air mass and a warm air mass are predicted to meet. What type of weather can be expected between the two air masses?
A.
warm weather
B.
cold weather
C.
dry weather
D.
stormy weather
Answers
Answer:
Explanation:
C. warm weather
Answer:
stormy weather
Set Grouper to 70%. How do you think this level of fishing will affect the populations of the other fish in the simulated reef? Explain your reasoning.
Answers
Answer:
Greatly affect.
Explanation:
This level of fishing will greatly affect the populations of the other fish in the simulated reef because overfishing disturbs the equilibrium in the marine ecosystem. One fish is a food of another fish or the big fish act as a controller which controls the population of other small fishes and in that way the ecosystem is present in equilibrium state so overfishing will greatly affect the marine ecosystem.
When 271. mg of a certain molecular compound X are dissolved in 25.0g of benzene C6H6, the freezing point of the solution is measured to be 0.5°C. Calculate the molar mass of X.
If you need any additional information on benzene, use only what you find in the ALEKS Data resource. Also, be sure your answer has a unit symbol, and is rounded to 2 significant digits.
molal freezing point depression constant (Kf)
°C·kg·mol−1 of benzene is 5.07
Answers
Answer:
11g/mol is the molar mass of X
Explanation:
The freezing point depression occurs in a solvent by the addition of a solute. The equation is:
ΔT = Kf*m*i
Where ΔT is change in freezing point (5.5°C - 0.5°C = 5.0°C)
Freezing point of benzene is 5.5°C
Kf is molal freezing point depression of benzene (5.07°C*kg/mol)
m is molality of the solution in moles/kg of solvent
And i is Van't Hoff factor (1 for all solutes dissolved in benzene)
Replacing to solve molality:
5.0°C = 5.07°C*kg/mol*m*1
0.986mol / kg = molality
As the mass of the solvent is 25.0g = 0.025kg:
0.025kg * (0.986mol/kg) = 0.0247 moles
As molar mass of X is the ratio between mass in grams and moles, the molar mass of X is:
0.271g / 0.0247moles =
11g/mol is the molar mass of XCalculate the percent composition (percent by mass of each element) of NH4Cl.
Round to the nearest ONES place ((example: 12.34% = 12%))
Answers
Answer:
[tex]\%N=26.2\%\\\\\%H=7.5\%\\\\\%Cl=66.3\%[/tex]
Explanation:
Hello!
In this case, since the calculation of the percent composition of an element in a chemical compound is computing considering its atomic mass, subscript in the formula and molecular mass of the compound it is; for nitrogen, hydrogen and chlorine we have that ammonium chloride has a molar mass of 53.49 g/mol so the percent compositions are:
[tex]\%N=\frac{14.01*1}{53.49}*100\% =26.2\%\\\\\%H=\frac{1.01*4}{53.49}*100\% =7.5\%\\\\\%Cl=\frac{35.45*1}{53.49}*100\% =66.3\%[/tex]
Best regards!
Gravity pulls rain and snow down to Earth from the atmosphere through a paire
process called precipitation Water is pulled from elevated areas such as
mountains and hills into lakes, oceans, and water reserviors. What is this
describing?*
role of gravity in the water cycle
role of gravity in condensation
O
role of gravity in evaporation
role of gravity in precipitation
Answers
Name the alkyne. Spelling and punctuation count. A seven carbon chain with a triple bond between carbon 1 and carbon 2. There is a C H 2 C H 2 C H 3 group attached to carbon 3.
Answers
Answer: IUPAC name of [tex]CH\equiv C-CH_2-CH_2-CH_2-CH_2-CH_3[/tex] will be hept-1-yne.
Explanation:
The IUPAC nomenclature of organic compounds are given as follows:
1. Select the longest possible carbon chain.
2. For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'hept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.
3. A suffix 'yne' is added at the end of the name if triple bond is present.
[tex]CH\equiv C-CH_2-CH_2-CH_2-CH_2-CH_3[/tex]
The IUPAC name will be hept-1-yne.
*SCIENCE*
A nebula contains large amounts of dust and clouds. What role does gravity play inside of nebulae?
0 The gravitational pull between the gas and dusť matter leads to the formation of new galaxies.
0 The gravity pulls the gas and dust apart, leading to the formation of a larger nebula.
0 The gravitational pull between the gas and dust matter leads to the formation of new stars and planets.
0 There is no gravity inside nebulae because each dust particle is so small.
Answers
Answer:
The gravitational pull between the gas and dust matter leads to the formation of new galaxies
Explanation:
My teacher went over the answers and said that one was correct.
A nebula contains large amounts of dust and clouds. The gravitational pull between the gas and dusť matter leads to the formation of new galaxies does gravity play inside of nebulae. Therefore, option A is correct.
What is gravity ?Gravity is the force that pulls objects toward the center of a planet or other body. The gravitational force keeps all the planets in orbit around the sun.
Gravity pulls you toward the ground because all objects with mass, such as our Earth, actually bend and curve the fabric of the universe, known as spacetime. Gravity is the curvature of the earth.
A nebula is densely packed with dust and clouds.The gravity play a role inside nebulae, The gravitational pull between gas and dus matter leads to the formation of new galaxies.
Thus, option A is correct.
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Which of the sets below are not in the order of lowest energy to highest energy: (A. 1s, 2s, 2p, 3s) (B. 2p, 3s, 3p, 4s) (C. 3s, 3p, 4s, 3d) (D. 3s, 3p, 3d, 4s)
Answers
Answer:
D
Explanation:
energy level order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s... (as periodic table shows)
what is the correct name of Fe(CN)3?
Answers
Answer:
Iron(III) Cyanide
For the reaction of ammonia (NH3) with oxygen (O2) to produce water and nitric oxide (NO), how many moles of water are produced when 2.2 moles of ammonia are reacted?
Answers
Answer:
3.3 moles of H₂O.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
4NH₃ + 5O₂ —> 6H₂O + 4NO
From the balanced equation above,
4 moles of NH₃ reacted to produce 6 moles of H₂O.
Finally, we shall determine the number of mole of H₂O produced by the reaction of 2.2 moles of NH₃. This can be obtained as follow :
From the balanced equation above,
4 moles of NH₃ reacted to produce 6 moles of H₂O.
Therefore, 2.2 moles of NH₃ will react to produce = (2.2 × 6)/4 = 3.3 moles of H₂O.
Thus, 3.3 moles of H₂O were obtained from the reaction.
Indium has a tetragonal unit cell for which the a and c lattice parameters are 0.459 and 0.495 nm, respectively. (a) If the atomic packing factor and atomic radius are 0.693 and 0.1625 nm, respectively, determine the number of atoms in each unit cell. (b) The atomic weight of indium is 114.82 g/mol; compute its theoretical density. (a) Enter your answer for part (a) in accordance to the question statement atoms/unit cell (b) Enter your answer for part (b) in accordance to the question statement g/cm3
Answers
Answer:
A) 4 atoms/unit cell
B) 7.31 g/cm^3
Explanation:
A) Determine the number of atoms in each unit cell
attached below is the detailed solution
number of atoms per unit cell ( n ) = 4 atoms/unit cell
B) Given atomic weight of indium = 114.82 g/mol
hence the theoretical density = 7.31 g/cm^3
Attached below is a detailed solution of the question
A student dissolves of aniline in of a solvent with a density of . The student notices that the volume of the solvent does not change when the aniline dissolves in it. Calculate the molarity and molality of the student's solution. Be sure each of your answer entries has the correct number of significant digits.
Answers
Answer:
Molarity: 0.21M
Molality: 0.20m
Explanation:
...dissolves 3.9g of aniline (C6H5NH2) in 200.mL of a solvent with a density of 1.05 g/mL...
To solve this question, we need to find the moles of aniline in 3.9g using its molar mass. Then, we need to find the kg and Liters of solution in order to find molarity (Moles/L solution) and molality (Moles/kg of solvent):
Moles aniline:
Molar mass:
6C: 6* 12.01g/mol = 72.06g/mol
7H: 7*1.008g/mol = 7.056g/mol
N: 1*14.007g/mol = 14.007g/mol
72.06g/mol+7.056g/mol+14.007g/mol = 93.123g/mol
Moles of 3.9g: 3.9g * (1mol / 93.123g) = 0.04188moles
Liters solution:
200mL * (1L / 1000mL) = 0.200L
kg solvent:
200mL * (1.05g/mL) * (1kg/1000g) = 0.210L
Molarity:
0.04188mol / 0.200L = 0.21M
Molality:
0.04188mol / 0.210L =0.20m
I need help with 17,18,19,& 21
Answers
Answer:
17. tie hair up
wear goggles
18. i don't know
19. you light it on the side of the box
20. it should be orange because that is the safest.
21. you turn down the electricity thing
helppp nowwww plssssss!!
Answers
A sample of a certain organic acid has a mass of 5.000 g. Elemental analysis of this compound found it to contain 1.334 g C, 3.554 g O, and the rest of the mass is hydrogen. If the molar mass of the organic acid is 90.03 g/mol, determine its molecular formula.
Answers
Answer:
C₂H₂O₄
Explanation:
Given parameters:
Mass of organic acid = 5g
Mass of C = 1.334g
Mass of O = 3.554g
Mass of H = 5 - (1.334 + 3.554) = 0.112g
Molar mass = 90.03g/mol
Unknown:
Molecular formula of the compound = ?
Solution:
To solve this problem, we find the empirical formula of the compound first. It is the simplest formula of the compound.
Elements C H O
Mass 1.334 0.112 3.554
Molar mass 12 1 16
Number of moles 1.334/12 0.112/1 3.554/16
0.112 0.112 0.222
Divide by the
Smallest 0.112/0.112 0.112/0.112 0.222/0.112
1 1 2
Empirical formula = CHO₂
The molar mass of this empirical formula = 12 + 1 + 2(16) = 45g/mol
Now;
Multiplication index = [tex]\frac{90.03}{45}[/tex] = 2
Molecular formula = (CHO₂)₂ = C₂H₂O₄
what happens to the electrons in a covalent bond?
Answers
Answer:
Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outer most (valence) electrons, atoms can fill up their outer electron shell and gain stability.
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Hydrogen is the only atom that does not
have __electrons in the 1st energy
level/ shell.
Answers
Answer:
2
Explanation:
the number of H is 1, it means the only electron is on the energy level (1st level, s-electron). All the elements have 2 s-electrons on the 1st energy level.
A tire contains 1.50 mol of air at a gauge pressure of 205 kPa. If the volume of the air in the tire is 0.0120 m3, what is its temperature
Answers
Answer:
197.07 K
Explanation:
To solve this problem we can use the PV=nRT equation, where:
P = 205 kPa ⇒ 205 * 0.00986 = 2.02 atmV = 0.0120 m³ ⇒ 0.0120 * 1000 = 12 Ln = 1.50 molR = 0.082 atm·L·mol⁻¹·K⁻¹ T = ?We input the data:
2.02 atm * 12 L = 1.50 mol * 0.082 atm·L·mol⁻¹·K⁻¹ * TAnd solve for T:
T = 197.07 KIn a chemical change
A. materials retain their properties.
B. materials change their properties.
C. new materials do not form.
D. new materials formed are always in liquid form.
Answers
Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
Chemical changes are not reversible. They lead to the production of new kinds of matter It involves mass changesRequires considerable amount of energyWhat are the non-living things that make up an ecosystem?
Answers
Answer:
abiotic things
abiotic things aren't living
Answer:
The non-living things would be the soil, rocks, and water. There are other things, but those are the main ones.
Suppose two students grab an end of a rope. Both shake a rope once in a upward direction to create crests traveling at each other. What would you see when crests meet? What type of interference does this show?
Answers
Answer:
This creates destructive interference.
Explanation:
When the two ends meet they will cancel each other out.
Both students are shaking the rope in the upward direction. Hence their crest will meet up and form the constructive interference pattern. The intensity of the increases.
What is constructive interference ?When two waves moves in phase, their crest or troughs add up and the amplitude of the wave increases. This phenomenon is called constructive interference.
If the two waves are passing out of phase to each other then they undergo destructive interference. The amplitude of the destructive interference pattern reduces from their initial values.
Here, both students are shaking the rope in the upward direction. Thus, they are in moving in phase. Hence their crest will meet up and form the constructive interference pattern. The intensity of the increases.
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Will measuring the melting point of your product tell you that your product is relatively pure?
Answers
Answer and Explanation:
Yes. The determination of melting point is used to analyze if a solid compound is pure or impure. The melting point of a pure solid product does not vary in a narrow range, whereas if impurities are present the solid melts in a broad range of temperatures. For this reason, this technique is generally used to determine the identity and purity of the products obtained in chemical reactions.
Magnesium reacts with a silver nitrate solution
The reaction is represented by the ionic equation given
State why this reaction is considered a redox reaction
Answers
Answer: Mg oxidised to Mg++ and Ag+ reduced to Ag
Explanation:No ionic equation given!!
assume equation is Mg + 2Ag+ + 2NO3- —> Mg++ + 2Ag + 2NO3-
redox reaction: Ag gains an electron = reduced
Mg loseselectrons = oxidised
Every morning, Jeremiah uses a blender to make a smoothie for breakfast. Which of the
following shows the energy transformation that the blender demonstrates?
А
Electrical - light
B
Chemical → mechanical
с
Mechanical → chemical
D
Electrical mechanical
Answers
Answer:
D
Explanation:
Answer:
D: Electrical -> mechanical
Explanation:
Hope this helps!
The diagram below represents the organizational levels of living things.
organisms
organ systems
?
tissues
cells
Which of the following examples represents the missing organizational level?
A blood
B heart
C plasma
D vein
Answers
Answer: its vein
Explanation:
Answer: It’s blood
Explanation:
I did the quiz
Bond length is the distance between the centers of two bonded atoms. On the potential energy curve, the bond length is the internuclear distance between the two atoms when the potential energy of the system reaches its lowest value. Consider that the atomic radius (sometimes called the covalent or bonding atomic radius) of an element is defined as one-half the distance between the bonded atoms in a homonuclear diatomic molecule. Actual bond lengths in molecules are determined experimentally by such methods as X-ray diffraction and microwave spectroscopy. However, these atomic radii values can be used to give an estimate of the upper limit of bond length in other (heteronuclear) molecules. Given that the atomic radii of H and Br are 37.0 pm and 115 pm , respectively, predict the upper limit of the bond length of the HBr molecule.
Answers
Answer:
152 pm
Explanation:
According to the question, we can estimate the bond length from the given values of the atomic radii. This now is the upper limit of the bond length for the molecule.
Since we have that;
Atomic radius of H= 37.0 pm
Atomic radius of Br = 115.0 pm
Bond length = Atomic radius of H + Atomic radius of Br
Bond length = 37.0 pm + 115.0 pm
Bond length = 152 pm
How can you model the cycling of matter in the Earth system?
Answers
Answer:
The cycling of matter is important to many Earth processes and to the survival of organisms the existing matter must cycle continuously for this planet to support life Water, carbon, nitrogen, phosphorus, and even rocks move through cycles If these materials did not cycle, Earth could not support life.
Explanation:
Earth activities depend on matter cycling, and for organisms to survive, this planet's surface must cycle with the flow of matter.
What is Earth system?Rocks, as well as water, carbon, nitrogen, and phosphorus, go through cycles. The planet Earth could not support life if these materials did not cycle.
Subsystems exist within the Earth system. These subsystems include the exosphere, atmosphere, hydrosphere, lithosphere and geosphere, also referred to as the lithosphere, and the living environment (biosphere).
These systems are powered by energy that comes from both the Sun and the interior of the Earth. Through processes known as biogeochemical cycles, nutrients and elements also move through these systems along with energy.
Therefore, Earth activities depend on matter cycling, and for organisms to survive, this planet's surface must cycle with the flow of matter.
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BALANCE THAI CHEMICAL EQUATION PLS, help:)
Answers
Answer:
4C₈H₄OH + 35O₂ → 32CO₂ + 10H₂O
Explanation:
The unbalanced reaction expression is given as:
C₈H₄OH + O₂ → CO₂ + H₂O
To solve this problem, we use a mathematical approach.
aC₈H₄OH + bO₂ → cCO₂ + dH₂O
Conserving C: 8a = c
H: 5a = 2d
O: a + 2b = 2c + d
Let a = 1, c = 8, d = [tex]\frac{5}{2}[/tex], b = 35
4C₈H₄OH + 35O₂ → 32CO₂ + 10H₂O
Based on your observations, why do you think the temperature of the NaC2H3O2 solution rose while that of the KCl solution fell
Answers
Answer:
Due to exothermic and endothermic reaction.
Explanation:
The temperature of NaC2H3O2 solution rises because exothermic reaction takes place in the solution while on the other hand, the temperature of KCl solution fell because endothermic reaction takes place. In exothermic reaction, heat energy is released to the surrounding whereas in endothermic reaction, heat energy is absorbed from the surrounding so that's why the temperature of one solution increases while the other decreases.