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Question: <p>Here is the question:</p>
<blockquote>
<p>For the reaction:
<span class="math-container">$$\ce{2 A + 2 B → C + D}$$</span></p>
<p>The following data was obtained from three experiments:
<span class="math-container">\begin{array}{c|ccc}\hline
\bf{Experiment} &\textbf{[A] (mol/L)} &\textbf{[B] (mol... | https://chemistry.stackexchange.com/questions/152863/finding-the-rate-of-a-reaction-given-experimental-data-for-reaction-kinetics |
Question: <p>It is given that when we use $50{-}\pu{60\%}\ \ce{KOH}$ in a Cannizaro reaction of formaldehyde, the reaction follows third order kinetics, but under special cases of Cannizaro reactions it was given than when formaldehyde reacts with $\pu{100\%}\ \ce{NaOH/KOH}$ the reaction follows fourth order kinetics.<... | https://chemistry.stackexchange.com/questions/88145/special-case-of-cannizaro-reaction-of-formaldehyde-with-100-naoh-koh-follows-4t |
Question: <p>I am modelling a methanation process in MATLAB, where I have a rate equation for methanation</p>
<p><span class="math-container">$$\ce{CO2 + 4 H2 → CH4 + 2 H2O}$$</span></p>
<p>in which I need partial pressure of <span class="math-container">$\ce{CO2},$</span> <span class="math-container">$\ce{H2},$</span>... | https://chemistry.stackexchange.com/questions/136134/kinetics-of-sabatier-reaction |
Question: <p>From the Arrhenius equation in kinetics of reactions,</p>
<p>$$k = A\exp{\left(-\frac{E_\mathrm{a}}{RT}\right)}$$</p>
<p>Which tells us about <strong>the temperature dependence on rate constant of a reaction.</strong></p>
<p><strong>Activation energy is dependent on the temperature</strong> (as it is th... | https://chemistry.stackexchange.com/questions/43576/chemical-kinetics-of-a-reaction-rate-constant-and-activation-energy |
Question: <p><a href="https://i.sstatic.net/mrjg4.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mrjg4.jpg" alt="So this is the question, hope someone can help."></a></p>
<p>For a hypothetical elementary reaction(image).
Initially, only 2 moles of A are present. The total number of moles of A, B, and C... | https://chemistry.stackexchange.com/questions/125824/chemical-kineticshypothetical-elementary-reaction |
Question: <p>As an exercise in chemistry, I decided to observe the kinetics of the decay of thiosulfate ions in an acidic medium. As far as I am aware, it is a very well known exercise among chemists.</p>
<p>I found a paper in which the author uses a sodium thiosulfate solution with a concentration of 0.25 mol/L and su... | https://chemistry.stackexchange.com/questions/188374/kinetics-of-the-thiosulfate-and-hydrochloric-acid-reaction |
Question: <p>I get the concept that one can measure the rate of reaction by measuring the rate at which an equilibrium state reaches another equilibrium state after the system is perturbed (usually by heating). However, I do have an issue with it. Consider the reaction $$\ce{A <=> B}$$ </p>
<p>My lecture handou... | https://chemistry.stackexchange.com/questions/24416/how-to-make-sense-of-the-relaxation-method-for-measuring-reaction-kinetics |
Question: <p>I am confused as to how an order of a reactant (n or m) in the rate law can be negative. This means that increasing the concentration of a reactant would actually decrease its rate of disappearance. How does this make sense? Doesn't a higher concentration always allow for more collisions? Also, when the or... | https://chemistry.stackexchange.com/questions/26887/kinetics-order-of-reaction |
Question: <p>I am layman of chemistry. Latterly, I am asked to do an mathematical optimization task for a bio-chemical process, which contains a conditioning step to neutralize the sulfuric acid using ammonia hydroxide. I am trying to use the mathematical model of the reaction (kinetic model) to optimize the reaction t... | https://chemistry.stackexchange.com/questions/34340/is-there-a-way-to-find-the-kinetics-data-for-the-strong-acid-weak-base-reaction |
Question: <p>I am having trouble with the following question:</p>
<blockquote>
<p>Consider the following reversible reaction in which the reaction is first order in both
directions: $$\ce{[A] <=> [B]}$$ $k_\mathrm a$ is the rate constant for the forward reaction and $k_\mathrm b$ is the rate constant for the... | https://chemistry.stackexchange.com/questions/31047/chemical-kinetics-of-a-reversible-reaction |
Question: <p>I'm trying to understand and incorporate 9-species 19-reaction H2/O2 combustion mechanism into my numerical solver. The reaction mechanism in question is <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/kin.20036" rel="nofollow noreferrer">O'Conaire</a>. It seems that the paper is in some standard... | https://chemistry.stackexchange.com/questions/166777/understanding-uni-and-termolecular-reactions-in-combustion-kinetics |
Question: <blockquote>
<p>A reaction $\ce{A + 2 B -> C}$ is carried out in constant volume at $\pu{227 ^\circ C}$. the volume is $\pu{2 L}$. There is no $\ce{C}$ at the beginning. $[\ce{A}]_0 = \pu{0.035 mol L-1}$. $\ce{B}$ concentration changes over time.</p>
<p>\begin{array}{l|cccccccc}
t~(\pu{min})& 0 ... | https://chemistry.stackexchange.com/questions/86826/kinetics-of-a-2-b-c-reaction |
Question: <p>Consider two chemicals, $\ce{A}$ and $\ce{B}$ that react with each other to make $\ce{C}$ with a reaction rate $k$. The reaction can be expressed as $$\ce{A + B->C}$$ The equation expressing the rate of the reactions can be expressed as $$\frac{d[\ce{A}]}{dt}=\frac{d[\ce{B}]}{dt}=-\frac{d[\ce{C}]}{dt}=-... | https://chemistry.stackexchange.com/questions/83631/analytical-solution-for-kinetics-of-bimolecular-reaction |
Question: <p>The way kinetics is taught at the undergraduate level (Arrhenius and collision theory) chemical equilibrium is determined governed immensely by activation energy of the reaction. According to thermodynamics, however equilibrium is a function of free energy change. In a way, thermodynamics and kinetics seem... | https://chemistry.stackexchange.com/questions/25077/kinetics-vs-thermodynamics |
Question: <blockquote>
<p>Find <span class="math-container">$[\ce{C}]/[\ce{A}]$</span> for the following system at equilibrium:</p>
<p><a href="https://i.sstatic.net/tY2EA.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/tY2EA.png" alt="Cyclic reversible reaction ABC" /></a></p>
</blockquote>
<p>I know th... | https://chemistry.stackexchange.com/questions/168399/chemical-kinetics-for-cyclic-reversible-reaction |
Question: <p>In graph given below is a sequential first order reaction</p>
<p><span class="math-container">$$\ce{A ->[$k_1$] B ->[$k_2$] C}$$</span></p>
<p>For <span class="math-container">$k_2 \gg k_1$</span> the graph of concentration of <span class="math-container">$\ce{A}$</span>, <span class="math-container"... | https://chemistry.stackexchange.com/questions/174588/sequential-first-order-reaction-graph-in-chemical-kinetics |
Question: <p>I would like to know according to which we can state that there is a unique equilibrium of a closed chemical reaction network (at constant circumstances) without supposing mass-action kinetics if time is increasing beyond all limits. Can we derive it from a non-equilibrium thermodynamic law or is it a post... | https://chemistry.stackexchange.com/questions/54519/what-guarantees-that-there-is-a-thermodynamic-equilibrium-in-a-closed-chemical-r |
Question: <p>What does it mean when the order of reaction isn't an integer, e.g., a reaction order of 2.43. Not with something acting as a catalyst but rather as a inhibitor. Why does the inhibitor produce an unusual reaction order? Specifically fluoride ions slowing down the reaction between calcium carbonate and acid... | https://chemistry.stackexchange.com/questions/42145/how-does-a-reaction-exhibit-kinetics-with-a-non-integer-reaction-order |
Question: <p>Can one be understood on the basis of the other or are they not interrelated at all?</p>
<p>The first thing my kinetics textbook demonstrated was how thermodynamics ignores time taken for a process whereas kinetics considers the time and rate of the process and hence kinetics is a more effective way to vi... | https://chemistry.stackexchange.com/questions/44155/what-is-the-relation-between-chemical-thermodynamics-and-chemical-kinetics |
Question: <p>According to the referenced paper, VR has an AChE inhibition reaction rate constant almost 4 times that of VX. Interestingly, its reaction rate constant for aging of the enzyme is less than that of VX, despite the fact that, as acknowledged by the authors of the paper, aging tends to occur faster when the ... | https://chemistry.stackexchange.com/questions/147164/differences-in-ache-inhibition-kinetics-between-vx-and-vr |
Question: <p>When we perform a organic reaction without any addtional catalyst except that the reaction is carried out under microwave condition we can accelerate this reaction in comparison with one under heating only. So, microwaves can be considered a form of catalysis according to the concept of reaction kinetics?<... | https://chemistry.stackexchange.com/questions/142850/organic-catalysis-microwaves |
Question: <p>The rate of reaction is given by the following equation, where [Ker-S-S-Ker] is just the molecule being broken down and [RSH] is an abbreviation for thioglycolic acid</p>
<p>The thioglycolate is in large excess and so essentially remains unchanged.</p>
<p><a href="https://i.sstatic.net/eQb9Q.png" rel="nofo... | https://chemistry.stackexchange.com/questions/144756/rate-of-change-and-kinetics-order-of-reaction-question |
Question: <p>I'm trying to understand what are the main factors that influence the reaction rate of an irreversible exothermic reaction. </p>
<p>I think these could be the main factors: </p>
<ol>
<li>chemical nature of the reagents and their concentration;</li>
<li>nature of the solution (homogeneous or heterogeneous... | https://chemistry.stackexchange.com/questions/91147/factors-that-influence-the-kinetics-of-an-irreversible-exothermic-reaction |
Question: <p>The answer is A, but how is that? I know B is an intermediate, so that after short time it will be bigger than C, but what does "thermodynamic control" and "kinetic control" mean?</p>
<p><a href="https://i.sstatic.net/7yoMM.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/7yoMM.png" alt="htt... | https://chemistry.stackexchange.com/questions/70344/how-do-thermodynamics-and-kinetics-control-this-reaction |
Question: <p>What will be the order of the reaction for a chemical change having <span class="math-container">$\log t_{1/2}$</span> VS <span class="math-container">$\log a$</span> Where <span class="math-container">$a=$</span> is the initial concentration of reactant and <span class="math-container">$t_{1/2} =$</span> ... | https://chemistry.stackexchange.com/questions/162616/finding-the-reaction-order-from-a-given-plot-of-chemical-kinetics |
Question: <p>It is always stressed that one should never mix Kinetics with Thermodynamic. How is it then possible to calculate the free energy of activation with the Arrhenius equation? As I understood, the Arrhenius equation and thus the activation energy of a reaction "belongs" to kinetics, whereas the free energy re... | https://chemistry.stackexchange.com/questions/74634/arrhenius-equation-in-kinetics-and-thermodynamics |
Question: <p>Why don't we take the effects of stirring and shaking on the rates of chemical reactions? While studying chemical kinetics, I've seen that the rates depend on the concentrations of various species, temperature, pressure, etc. But I've never seen an equation taking into account the mechanical stirring, shak... | https://chemistry.stackexchange.com/questions/150043/effect-of-stirring-and-shaking-on-chemical-kinetics |
Question: <blockquote>
<p>The reaction of tert-butyl bromide with azide ion in aqueous solution
is proposed to proceed by the following mechanism:</p>
<p>$\ce{(CH3)3CBr(aq) <=>(CH3)3C+(aq) + Br–(aq)}$</p>
<p>$\ce{(CH3)3C+(aq) + N3–(aq) \to (CH3)3CN3(aq)}$</p>
<p>Assuming that $\ce{(CH3)3C+ (aq)... | https://chemistry.stackexchange.com/questions/73243/chemical-kinetics-with-the-reaction-of-tert-butyl-bromide-with-azide-ion |
Question: <p>What optical methods can be used to measure the concentration of reacting gases in a reactor during an exothermic and fast reaction? I need to monitor and measure the <em>local concentration of my gases</em> (in the methane production reaction) along a reactor bed in order to be able to clarify the <em>kin... | https://chemistry.stackexchange.com/questions/80848/optical-techniques-for-kinetics-studies |
Question: <p>I know sodium metal reacts violently with water, but what about aqueous solutions (like sodium bicarbonate). Also, what would the reaction kinetics be? </p>
<p>I have watched YouTube videos were a small piece of elementary sodium reacts completely with water in a matter of seconds. Would that also be the ... | https://chemistry.stackexchange.com/questions/57351/would-sodium-metal-react-differently-with-aqueous-solutions-than-with-pure-water |
Question: <p>I just read about the theory of auto-catalysis, and here's one thing which is sort of unclear to me: </p>
<blockquote>
<p>In this type of catalysis, one of the reaction product catalyses the reaction. For example, in the oxidation of oxalic acid by potassium permanganate, Mn(II) cation is formed which i... | https://chemistry.stackexchange.com/questions/86979/auto-catalysis-mechanism |
Question: <p><strong>Prologue</strong>:</p>
<p>Recently started with <em>Chemical Kinetics</em> at class. Came across a couple of points in Levine's <em>Physical Chemistry</em> (the book was <a href="https://chemistry.stackexchange.com/questions/37303/resources-for-learning-chemistry">recommended on Chem.SE</a>; so I t... | https://chemistry.stackexchange.com/questions/81039/conceptual-tussle-with-kinetics-of-equilibrium-and-non-equilibrium-processes |
Question: <p>What is the difference between a loaded solution and an unloaded solution? I was reading this article and I didn't understand these parts:</p>
<blockquote>
<ul>
<li>The reaction kinetics of $\ce{CO2}$ with <strong>loaded</strong> aqueous MEA solution...</li>
<li>$\ce{CO2}$ <strong>loading</strong> f... | https://chemistry.stackexchange.com/questions/61780/loaded-and-unloaded-solutions |
Question: <p>This is for the hydrolysis of p-nitrophenyl phosphate by alkaline phosphatase, whereby the enzyme is in a solution of distilled water. We also add glycine buffer to the solution. It exhibits first-order kinetics, even though there is a second reactant (being water) - how is this possible?</p>
Answer: <p>I... | https://chemistry.stackexchange.com/questions/90475/how-can-a-reaction-exhibit-first-order-kinetics-when-there-is-more-than-one-reac |
Question: <p>My friends and I were doing some problems from this year's IChO Preparatory Problems (<a href="https://icho2017.sc.mahidol.ac.th/pdf/49th_IChO_PreparatoryProblem.pdf" rel="nofollow noreferrer">PDF from the 49th International Chemistry Olympiad (2017)</a>) when we stumbled upon a question which we had some ... | https://chemistry.stackexchange.com/questions/87363/half-life-equation-for-2nd-order-kinetics |
Question: <p>I have been recently studying chemical kinetics. I've understood what the rate law and the rate constant mean, and also that, kinetics depends completely on experimental observations, due to which we have zero order reactions as well as fractional order reactions.</p>
<p>Take for example, this: $$\text{Ra... | https://chemistry.stackexchange.com/questions/82089/query-in-chemical-kinetics |
Question: <p>In an interview for post-grad level, I was asked to explain the "order" of any generic enzymatic reaction involving <a href="https://chem.libretexts.org/Bookshelves/Biological_Chemistry/Book%3A_Biochemistry_Online_(Jakubowski)/08%3A_Transport_and_Kinetics/8.4%3A_Enzyme_Inhibition/Competitive_Inhi... | https://chemistry.stackexchange.com/questions/165992/order-in-enzyme-kinetics |
Question: <p>Starting from the equations of <a href="http://en.wikipedia.org/wiki/Law_of_mass_action" rel="nofollow">mass action kinetics</a>, one may show that (for suitably chosen numbers $A_i$), the function $\sum_i x_i(A_i + \log x_i)$ is a <a href="http://en.wikipedia.org/wiki/Lyapunov_function" rel="nofollow">Lya... | https://chemistry.stackexchange.com/questions/19234/what-is-the-non-ideal-equivalent-of-mass-action-kinetics |
Question: <p>when a chemical bond is formed, does chemical reaction occur? if i have done a coating on metal substrate then how does it adhere to the substrate? If there is a chemical bond then which reaction does takes place?</p>
Answer: <p>If a chemical bond between atoms is split, or newly generated, than there is ... | https://chemistry.stackexchange.com/questions/70494/chemistry-chemical-bonding |
Question: <p>Was studying chemical bonding(Valence bond theory) but there came this topic called <em>wave equation</em> but have not studied quantum mechanics,so finding hard to understand these terms.Please help!!!</p>
Answer: <p>$\Psi$ is the wavefunction describing an electron's motion. $\Psi^2$ is the probabilit... | https://chemistry.stackexchange.com/questions/9612/what-is-this-wave-function-in-chemical-bonding |
Question: <p>How does chemical bonding look like on the quantum scale per se since the electron is a wave, and a particle?</p>
Answer: <p>I believe that generally in chemistry the wave characteristics of the electron are far more prevalent/relevant that the particle characteristics. So it's usually easiest just to thi... | https://chemistry.stackexchange.com/questions/46959/what-does-chemical-bonding-look-like-at-the-quantum-level |
Question: <p>How exactly does bonding work?
For example, in CH4 orbital overlap structure, the internet shows 4 lobes with one hydrogen attached to each...</p>
<p><a href="https://i.sstatic.net/f9yPx06t.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/f9yPx06t.gif" alt="enter image description here" /></a... | https://chemistry.stackexchange.com/questions/186037/chemical-bonding |
Question: <p>I would like to ask how many valence electrons took part in creating chemical bond in $\ce{OH-}$? Is the minus related to $\ce{O}$ or to $\ce{H}$? Are there any spare valence electrons which didnt take part in creating chemical bond in $\ce{OH-}$?</p>
Answer: <p><img src="https://i.sstatic.net/BtYqt.jpg" ... | https://chemistry.stackexchange.com/questions/7264/chemical-bond-covalent-valence-electrons-oh |
Question: <p>How do we compare the strength of permanent dipole permanent dipole (PDPD) interaction? Is it by bond polarity?
Since H-X (where X is halogen) is polar, and for bond polarity (PDPD bond strength): HCl > HBr > HI, why is it that for boiling point: HCl < HBr < HI which is inversely proportional to bon... | https://chemistry.stackexchange.com/questions/87917/chemical-bonding |
Question: <p>My chemistry teacher told me that chemical bonds are of two types: intramolecular and intermolecular. He said that intermolecular forces come under the category of intermolecular chemical bond. </p>
<p>I have never read such statement anywhere. Nor can I find anything on the Internet that would support th... | https://chemistry.stackexchange.com/questions/91369/are-intermolecular-forces-a-type-of-chemical-bond |
Question: <p>When oxygen is adsorbed on iron metallic surface, does it create $\ce{Fe-O}$ bonds like the one in iron oxide? Can it be considered as a monolayer of iron oxide on the surface?</p>
<p>If not, how is the atomic bond of adsorbed oxygen and iron? How much is it strong? and what is its difference with normal ... | https://chemistry.stackexchange.com/questions/16475/chemical-bond-of-adsorbed-atoms |
Question: <p>I am trying to find out what chemical bond holds aluminum oxide to the aluminum on which it forms. The only information I was able to find on the internet was in a Google book which suggested that the bond was ionic in nature.</p>
Answer: | https://chemistry.stackexchange.com/questions/38505/chemical-bond-at-aluminum-aluminum-oxide-interface |
Question: <p>VSEPR theory correctly predicts the shapes of many symmetry-broken molecules such as $\ce{H2O}$ and $\ce{NH3}$. Take $\ce{NH3}$ for example. In VSEPR theory, the nitrogen atom is (approximately) at the center of a tetrahedron, the three $\ce{N-H}$ bonds point to three of the four vertices of the tetrahedro... | https://chemistry.stackexchange.com/questions/89244/vsepr-theory-chemical-bond-and-quantum-mechanics |
Question: <p>While superheavy elements are notoriously unstable, there's plenty of theoretical research and even some experimental techniques are valid for nuclides decaying in a matter of seconds. They can verify presence of relativistic effects, which may cause behavior defying expectations</p>
<p>How do the relativi... | https://chemistry.stackexchange.com/questions/184390/how-do-the-relativistic-effects-influence-chemical-bonding-of-hassium-or-other-c |
Question: <p>Question: Why is ionic lattice energy inversely proportional to the radius of the atom?</p>
<p>Most heterogeneous covalent molecules are polar to some extent. The degree of polarity, or the dipole moment, depends on the difference in electronegativity difference between the two atoms. The larger the dipol... | https://chemistry.stackexchange.com/questions/14132/chemical-bonding-lattice-energy |
Question: <p>I have IR spectra of polystyrene with characteristic peaks at 1450cm-1. 1500cm-1 and 1600cm-1. What chemical bond is associated with 1600cm-1 and 1500cm-1?</p>
Answer: <p>As shown <a href="https://www.spectroscopyonline.com/view/the-infrared-spectra-of-polymers-iii-hydrocarbon-polymers" rel="nofollow nore... | https://chemistry.stackexchange.com/questions/167866/help-with-chemical-bond-associated-with-1500cm-1-and-1600cm-1 |
Question: <p>We know that ammonia undergoes amine inversion. Why doesn't the dipole moment decrease in ammonia, since the direction of the dipole changes to the opposite direction every time there's inversion?</p>
<p>Shouldn't the effective dipole moment become zero?</p>
Answer: <p>Ivan Neretin is correct in stating ... | https://chemistry.stackexchange.com/questions/62262/chemical-bonding-and-dipole-moment |
Question: <p>For the elements such as rhenium, osmium, iridium how probable is for electrons in the inner 4f orbitals to gain energy and take part in a molecular orbital (such as an $f^2 d^2 s p^3$ hybrid orbital) when these elements are in their 6,7,8,9 oxidation state? </p>
Answer: <p>By transition metals, 4f become... | https://chemistry.stackexchange.com/questions/78542/chemical-bonding-with-f-orbitals |
Question: <p>We can explain chemical anti-bonding just using the Pauli repulsion correct?Let's take He2.</p>
<p>2 atoms of He share 4 1s electrons and since the magnetic spin for electrons has 2 values there would be 2 electrons with the same wave function which would violate the Pauli exclusion principle.This makes H... | https://chemistry.stackexchange.com/questions/123448/chemical-anti-bonding-and-pauli-repulsion |
Question: <p>What happens to the lobe of the p-orbital during sp² hybridization?</p>
<p>During the formation of <span class="math-container">$\ce{C2H4}$</span> molecule:</p>
<p>We know that both the carbon atoms will have a total of 3 p-orbitals and they will be involved in hybridization.</p>
<p>Let us number the ca... | https://chemistry.stackexchange.com/questions/24989/chemical-bonding-and-hybridization-of-organic-compounds |
Question: <p>A snippet from a textbook:</p>
<blockquote>
<p>Therefore, the hybridization model predicts that an <span class="math-container">$\mathrm{sp}$</span>-hybridized carbon atom is more electronegative than an <span class="math-container">$\mathrm{sp}^3$</span>-hybridized carbon atom. Evidence for this effect... | https://chemistry.stackexchange.com/questions/109261/chemical-bonding-based-on-hybridisation-model |
Question: <p>In books it is commonly written that whenever a chemical bond is formed the energy of the molecules/atoms gets lowered and hence energy is released. This is generally explained by diagrams like this </p>
<p><a href="https://i.sstatic.net/uXJub.jpg" rel="noreferrer"><img src="https://i.sstatic.net/uXJub.jp... | https://chemistry.stackexchange.com/questions/126598/how-energy-is-released-when-chemical-bond-is-formed |
Question: <p>Ionic bonds seem to be intermolecular but are classified as chemical bonds.</p>
<blockquote>
<p>"Ionic bonding is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions." - <em>Wikipedia, definition of an ionic bond</em></p>
<p>"The physical force... | https://chemistry.stackexchange.com/questions/32533/why-is-an-ionic-bond-a-chemical-and-not-a-physical-bond |
Question: <p>Chemical reactions are classed as endothermic or exothermic.</p>
<p>Defn: exothermic</p>
<blockquote>
<p>(of a reaction or process) accompanied by the release of heat.</p>
</blockquote>
<p>The heat is released when the chemical bonds in the product are formed.</p>
<p>Defn: heat</p>
<blockquote>
<p... | https://chemistry.stackexchange.com/questions/111936/how-is-energy-released-when-a-chemical-bond-is-formed |
Question: <p>In general is there a convention as to how one interprets squiggly lines in chemical structure notation?</p>
<p>e.g. see the below sketch. I suppose it has something to do with cis / trans isomerism. But e.g. where do you draw the squiggly i.e. which side of the double bond? Is it used in other contexts as... | https://chemistry.stackexchange.com/questions/145043/squiggly-line-in-chemical-bond-notation |
Question: <p>I would like to ask if the 3D spacing arrangement of atoms in chemical bond configurations are always unique, please?</p>
<p>For example, glycine consists of the set of atoms HHNCHHCOOH. Does there exist a different stable 3D arrangement of this collection of atoms, other than:</p>
<p><a href="https://i.ss... | https://chemistry.stackexchange.com/questions/163336/is-the-3d-spacing-arrangement-of-atoms-in-chemical-bond-always-unique |
Question: <p>I'm working on a chemistry question where I'm supposed to use average bond energies to estimate enthalpy changes for a reaction. It gives me these bond energies to work with:</p>
<p>$$\begin{align}
\ce{C-H}&=&413\\
\ce{C-C}&=&348\\
\ce{C-Br}&=&276\\
\ce{H-Br}&=&366\\
\ce{Ck... | https://chemistry.stackexchange.com/questions/93953/what-does-ckc-mean-in-chemical-bonding |
Question: <p>I can understand that in Silicon Crystal a central Silicon atom shares its 4 valance electrons with 4 surrounding silicon atoms. And the chain continues. But then What happens to the outermost such Silicon atoms (in the drawing). They each will have incomplete so called octate.</p>
Answer: <p>In a Silicon... | https://chemistry.stackexchange.com/questions/133493/chemical-bonding-and-crystal-structure-of-silicon |
Question: <p>I recently came across a question in which an option is 'Breaking a chemical bond is the first step in any chemical reaction', which lead me to think of reactions which do not involve bond breaking. The only reaction I can think of is dimer formation, but a Google search reveals no more. Surely this cannot... | https://chemistry.stackexchange.com/questions/99967/which-chemical-reactions-dont-involve-bond-breaking |
Question: <p>As we know, the first excited states of Hydrogen atoms is $2p$.
The wave functions in cartesian basis we can represent as
$$
p_x = \frac{1}{\sqrt{2}} \left( Y_{1, +1} + Y_{1, -1}\right) =\sqrt{\frac{3}{16\pi}} \frac{x}{r} \\
p_y = \frac{i}{\sqrt{2}} \left( Y_{1, +1} - Y_{1, -1}\... | https://chemistry.stackexchange.com/questions/68768/spatial-form-of-an-atom-and-type-of-chemical-bond |
Question: <p>We know that if Cl and Na get too close, they produce ionic bonding.</p>
<p>Cl has 17 proton and 17 electrons and is considered stable.</p>
<p>Na has 11 protons and 11 electrons and is considered stable.</p>
<p>I understand that in Na, we have 1 valence electron and in Cl, we have 7 valence electrons. Now,... | https://chemistry.stackexchange.com/questions/173378/why-chemical-bond-between-na-and-cl-happens |
Question: <p>How can the formation of a covalent bond be described from a quantum perspective, and what implications does it have for traditional chemical bonding theory?</p>
<p>Specifically, in the context of many-electron systems where electron correlation becomes significant, how do modern quantum chemical methodolo... | https://chemistry.stackexchange.com/questions/175972/quantum-chemistry-and-covalent-bonding |
Question: <p>In a hypothetical (?) Og<sub>2</sub><sup>+235</sup> we would have a simple sigma bonding orbital occupied by one electron (leading to a bond order of 1/2). But how to take into account the giant repulsion of the two nuclei? Generally how are nucleis taken into account for energy calculations from molecular... | https://chemistry.stackexchange.com/questions/169595/would-a-hypothetical-og2-235-form-a-chemical-bond |
Question: <p>Here's a "simple" bond diagram of 1,1,1,2-Tetrafluoroethane which I believe is a Lewis structure:</p>
<p><a href="https://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/1,1,1,2-Tetrafluoroethane.svg/100px-1,1,1,2-Tetrafluoroethane.svg.png" rel="nofollow noreferrer"><img src="https://upload.wikimedia.or... | https://chemistry.stackexchange.com/questions/14460/explanation-of-certain-chemical-bond-diagrams |
Question: <p>Both in fine art, decorative and in utilitarian painting, sanding or roughening a substrate to provide a so-called “mechanical bond” has often been recommended as a preliminary step before applying paint.</p>
<ol>
<li><p>Interestingly, sanding is said to both roughen a surface, giving it some “tooth” for p... | https://chemistry.stackexchange.com/questions/187939/is-a-chemical-molecular-bond-considered-more-effective-for-paint-adhesion-than |
Question: <p>I'm working with an amorphous system. With oxygen, my system has both covalent and ionic bond forming cations. I utilise the <a href="https://en.wikipedia.org/wiki/Wannier_function" rel="nofollow noreferrer">Wannier centre</a> to define a covalent bond, and my theory is that if the Wannier centre is near t... | https://chemistry.stackexchange.com/questions/165918/how-to-define-a-chemical-bond-computationally |
Question: <p>In a paper by Peng <em>et. al.</em>,<sup>[1]</sup> I read about the valence band maximum of <span class="math-container">$\ce{TiO2}$</span> consists of <strong>non-bonding O p<sub>π</sub></strong> orbitals</p>
<blockquote>
<p>... the valence band maximum (VBM) consists of non-bonding O p<sub>π</sub> states... | https://chemistry.stackexchange.com/questions/157594/what-does-it-mean-by-non-bonding-p-pi-orbital |
Question: <p>My main question is why is the boiling point of methanol so much different from that of water? </p>
<p>I understand that both compound are able to develop hydrogen bonding, and obviously water can develop one more hydrogen bond than methanol. </p>
<p>But on the other hand:</p>
<blockquote>
<p>Due to p... | https://chemistry.stackexchange.com/questions/76727/how-does-hydrogen-bonding-affect-the-boiling-points-of-chemical-compounds |
Question: <p>This question has to do with the idea of stability and energy. The premise is that systems will tend towards lower energy states, that’s why bonding happens and electrons prefer single orbitals. And that makes sense in all considering the second law of thermodynamics, but it still doesn’t answer what cause... | https://chemistry.stackexchange.com/questions/176232/how-does-a-reduction-in-potential-energy-in-a-chemical-bond-release-energy |
Question: <p>My question related with another one <a href="https://physics.stackexchange.com/questions/387723/shape-of-hydrogen-atom-in-excited-state-with-nonzeros-angular-momentum">here</a>.</p>
<p>For explanation valence bond direction chemists are used real wave functions, for example $p_x, p_y, p_z, \ldots$. But t... | https://chemistry.stackexchange.com/questions/91050/using-real-wave-functions-for-chemical-bond-explanation |
Question: <p>I understand the geometry and calculation of a dihedral angle, discussed in <a href="https://math.stackexchange.com/q/47059/221321">this question</a>. It is not clear how the direction is defined for a chemical bond. On the <a href="https://en.wikipedia.org/wiki/Dihedral_angle" rel="nofollow noreferrer">w... | https://chemistry.stackexchange.com/questions/40181/when-calculating-a-dihedral-angle-for-a-chemical-bond-how-is-the-direction-defi |
Question: <p>With respect to chemical bonding does the $\ce{I2-}$ ion exist?</p>
Answer: <p>I found a <a href="http://pubs.acs.org/doi/pdf/10.1021/jp0671087" rel="nofollow noreferrer">paper</a><span class="math-container">$\ce{^{[1]}}$</span> regarding the formation of diiodide anion species(<span class="math-containe... | https://chemistry.stackexchange.com/questions/87971/does-the-diiodide1%e2%88%92-anion-exist |
Question: <p>My textbook says:</p>
<blockquote>
<p>It is appropriate to remark that the trick of rationalizing apparent violations of the octet rule by invoking the participation of d-orbitals in the bonding scheme is a matter of some controversy. Some scientists feel that the d-orbitals lie so high in energy that they... | https://chemistry.stackexchange.com/questions/33869/can-d-orbitals-participate-in-bonding |
Question: <p>Do the antimatter molecules have the same chemical properties with matter molecules?Should we define electropositivity for antimatter molecules since the chemical bonding would be between positrons?</p>
Answer: <p>The following is an approximation based on the most accepted theories about cosmology (that ... | https://chemistry.stackexchange.com/questions/116704/antimatter-molecules-properties |
Question: <p>This is more of a terminology question. How are phase changes considered a physical property, not a chemical property when hydrogen bonds break. A chemical property can only be observed during a chemical change. Aren't hydrogen bonds a type of chemical bond, and those bonds are being broken during a phase ... | https://chemistry.stackexchange.com/questions/85906/if-hydrogen-bonds-are-chemical-bonds-and-these-bonds-are-broken-when-water-chan |
Question: <p>Hi so I was studying chemical bonding where i encountered a problem which is stated below.</p>
<p>When we talk about <span class="math-container">${NO_3}^-$</span> we draw its structure as following
<img src="https://i.sstatic.net/Q8cda.jpg" alt="enter link description here">
But the thing which I dont un... | https://chemistry.stackexchange.com/questions/118527/bonding-in-the-nitrate-anion |
Question: <p>I don't know much about quantum mechanics, but I do know that it's quite far removed from the easily observable and that anything "quantum" involves things that are discreet. So, how close is the analogy between molecular bending and vibration with that of springs? Is there maybe a better way to think, may... | https://chemistry.stackexchange.com/questions/41889/if-chemical-bonding-is-quantum-mechanic-is-saying-they-bend-and-vibrate-like-sp |
Question: <p>I am reading an introductory semiconductor physics textbook. The textbook states the following:</p>
<blockquote>
<p>Several types of atomic bonding have been identified, including ionic, covalent, van der Waals, hydrogen, and metallic. Whatever the name given to the type of bonding, in all cases it is t... | https://chemistry.stackexchange.com/questions/111708/textbook-claim-in-all-cases-it-is-the-electrostatic-force-acting-between-c |
Question: <p>In general when we talk about chemical bonding, we say that it is "nature's way to stabilize the systems" and the energy of the molecule formed by atoms will be lower than that of the individual atoms; hence leading to stabilization. </p>
<p>However, while reading about the Molecular Orbital Theory in my ... | https://chemistry.stackexchange.com/questions/125090/energy-levels-of-molecular-orbitals-formed-by-combination-of-atomic-orbitals |
Question: <p><a href="https://simple.wikipedia.org/wiki/Molecule" rel="nofollow noreferrer">Wikipedia</a> says so:</p>
<blockquote>
<p>Bonds can also be broken apart. Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. T... | https://chemistry.stackexchange.com/questions/118911/does-it-sometimes-take-energy-to-create-a-chemical-bond |
Question: <p>My teacher was teaching about chemical bonding and she said that pi bond needs sigma bond to exist, but she didn't know why. It is a doubt which I get in my mind, can someone explain it?</p>
Answer: <p>I think it would be more correct to say that pi bonds tend to exist in conjunction with sigma bonds, rat... | https://chemistry.stackexchange.com/questions/58300/pi-bond-need-sigma-bond-to-exist |
Question: <p>My chemical bonding professor says that the $\ce{O-S-O}$ bond angles in $\ce{SO4^2-}$ are ideal (109.5°).</p>
<p>Why? Is this because all bonds are equivalent, and electron distribution is shared among all oxygens?</p>
Answer: <p>Yes. All the bonds are equivalent as in the 4 resonating structures, each w... | https://chemistry.stackexchange.com/questions/37875/bond-angles-in-sulfate |
Question: <p>If you characterize the chemical bonds to two categories physical and chemical bonds, how do you do it? Aren't all bonds <strong><em>chemical and physical</em></strong>?</p>
<p>From the freedictionary.com, chemical bond:</p>
<blockquote>
<p>Any of several forces, especially the ionic bond, covalent bon... | https://chemistry.stackexchange.com/questions/230/what-is-the-difference-between-physical-and-chemical-bonds |
Question: <p>So, if I have multiple FTIR spectra each taken on different location of the sample and averaged from ~20 spectra, how can I check if the sample is homogeneous, i.e., if there are statistically significant differences between the spectra based on location? For visuals, I tried to compute at each wavenumber ... | https://chemistry.stackexchange.com/questions/139661/statistical-methods-used-for-testing-the-homogeneity-of-the-sample |
Question: <p>Surface-enhanced Raman spectroscopy or surface-enhanced Raman scattering (SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough metal surfaces or by nanostructures such as plasmonic-magnetic silica nanotubes.</p>
<p>Does this require a Raman microscope? Rememb... | https://chemistry.stackexchange.com/questions/142749/can-you-do-sers-without-a-raman-microscope |
Question: <p>I am computing Franck-Condon Factors between the neutral ground state and cationic states to simulate the photoelectron spectra (using Gaussian 16, freq=FCHT). The target cationic state is a pi state and has 3/2 and 1/2 spin-orbit components. I have done optimization and frequency calculation for the pi st... | https://chemistry.stackexchange.com/questions/145328/how-to-compute-franck-condon-factors-for-spin-orbit-states |
Question: <p>I was thinking back to my chemistry major days and remembering the bunch of cool spectra we produced by various means (HNMR, IR, UV/Vis) and I remember all the cool 'self-interference' like couplets, triplets doublets, etc. </p>
<p>My question is basically motivated by the complexity of spectra, and the r... | https://chemistry.stackexchange.com/questions/3957/fourier-transform-for-spectroscopy-spectra |
Question: <p>I am in mathematics, but I am writing a paper on molecular vibrations (because you can use representation theory to handle this).</p>
<p>I want to prove the selection-rule, but I also have to give a presentation of my intermediate results. Can someone give a little (maybe trivial) explanation (in one or m... | https://chemistry.stackexchange.com/questions/4488/explanation-of-the-selection-rule-in-light-of-ir-spectroscopy |
Question: <p>I was trying to figure out the different peaks in a XPS spectrum for Molybdenum, but I could not understand them. About XPS, I know that this technique is based on the binding energy of the electrons of different elements</p>
Answer: <p>you are quite right, XPS does measure the 'binding energy' of electro... | https://chemistry.stackexchange.com/questions/4772/what-does-the-signals-in-a-xps-spectrum-mean |
Question: <blockquote>
<p>Using a state-of-the-art atomic force microscope, the scientists have taken the first atom-by-atom pictures, including images of the chemical bonds between atoms, clearly depicting how a molecule's structure changed during a reaction. Until now, scientists have only been able to infer this t... | https://chemistry.stackexchange.com/questions/5170/how-did-scientists-capture-the-first-images-of-molecules-before-and-after-reacti |
Question: <p>I know that elements (ex. Ag) have spectral/emission/absorption lines, but do chemical compounds (ex. NaCl) have spectral lines as well? Ones that when seen you can tell that that compound (NaCl) is made up of certain elements (Na and Cl).</p>
Answer: <p>Yes, but for "spectral lines" the gaseous state wou... | https://chemistry.stackexchange.com/questions/5235/do-chemical-compounds-have-spectral-lines-or-only-elements |
Question: <p>Are there any two distinct types of atom or molecule that have identical emission or absorption spectra?</p>
Answer: <p>In addition to the R/S chiral molecules mentioned by @user26143. There are also molecules with a distinct atomic composition that have experimentally indistinguishable spectra, even thou... | https://chemistry.stackexchange.com/questions/6994/are-there-any-molecules-with-the-same-spectrum |
Question: <p>I want to do some spectrometry experiments with glow in the dark paints. The red paints I've read product details for all seem to require a uv light to charge. Are there any red glow in the dark paints that can be charged with visible light?</p>
<p>I was also wondering why most red phosphorescent pigments... | https://chemistry.stackexchange.com/questions/7096/red-glow-in-the-dark-pigments |
Question: <p>Question is rather self-explanatory. Came up during a lecture without a concrete answer. </p>
<p>I understand that the differences in emission wavelengths is due to relaxation to the lowest energy level of S1, but <strong>why do fluorescent molecules necessarily overlap in their excitation and emission sp... | https://chemistry.stackexchange.com/questions/7235/why-does-the-excitation-and-emission-spectrum-of-a-fluorescent-molecule-have-ove |
Question: <p>Is visible spectroscopy the only non-electronic method of all the spectroscopy method?</p>
<p>I know some of the spectroscopy method is possible being used because of electronics.</p>
Answer: <p>No, Ultraviolet spectroscopy and Infra-red spectroscopy were practiced without any use of electricity. </p>
... | https://chemistry.stackexchange.com/questions/10928/is-visible-spectroscopy-the-only-non-electronic-method-of-all-the-spectroscopy-m |
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