A catalyst is a substance that increases the rate of a reaction without modifying the overall standard Gibbs energy change in the reaction; the process is called catalysis. This tag is appropriate for reactions, their mechanisms, their kinetics, when catalysts of any kind are involved.

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How slow is a ester reaction without a catalyst? (in a whiskey barrel?)

The typical description of a high school ester reaction of an alcohol and an organic acid uses a strong acid catalyst like HCl or ...
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What is an active centre of a catalyst?

I was studying catalytic poisoning and read that in temporary poisoning, the poisoners are held at active centres by weak forces. What is an 'active centre' in this context?
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Water side reactions in organic electrochemistry [closed]

Please bear with me as I am a chemistry newbie, but I am autistic and have recently developed a fixation on electrosynthesis and must understand it. I'm interested in split reaction systems, where a ...
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123 views

Explain why alumina-containing zeolites possess chemically active surfaces

I think zeolites possess acid sites that are catalytically active in many hydrocarbon reactions. The pore system only allows molecules that are small enough to enter, hence it affects the selectivity ...
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Zeolytes as Catalyst in hydrocracking

What is the working principle that allows zeolites to be catalysts in hydrocracking? Is it only their acidic ability to hold hydrogen and release to crack the oil?
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Can fluid catalytic cracking work on a smaller scale in a laboratory?

Fluid Catalytic Cracking usually requires a very large and tall structure. Is there a way of miniaturizing the process to fit inside a chemical lab with 10 ft ceilings? Specifically: can a fluidized ...
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Are there any suitable catalysts for ferric oxide and aluminum reaction?

As an exercise, I am trying to figure out how to catalyze the reaction of ferric oxide and aluminum Fe2O3 + 2Al -> 2Fe + Al2O3 I've been trying to find a substance A such that the reaction could be ...
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54 views

Volcano plots: How is the data fitted?

When studying about catalysts I normally come accross volcano plots like the one shown below: What confuses me is how are the two lines fitted, how do you determine what points to include and what ...
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Effect of His-tag on enzyme activity

In my biochemistry laboratory class, I designed an experiment to study the effect of a His-tag on enzyme activity. First, I measured the activity of the His-tagged enzyme. Then, I cut off the His-tag (...
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104 views

Why does NaOH catalyze H2O2 decomposition? [duplicate]

I had a lab practice in which I had to test the effectiveness of different catalysts for the decomposition of $\ce{H2O2}$. Among them, there was: $\ce{KI(aq)}$, $\ce{FeCl3(aq)}$, $\ce{MnO(s)}$, $\ce{...
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Electrocatalysis of Hydrogen Evolution Reaction with metal oxides

I'm new in this topic of electrocatalysis so I have some doubts. Also I´m not to clear with the themordynamic backgorund, so I will try to ask with the little thing that I know. I'm looking for a ...
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The chlorofluorocarbon reaction in the lab?

The putative reason for banning Freon and its class of chemical (chlorofluorocarbons) is that they will rise to the top of the atmosphere, to the ozone layer and "catalyze" the reduction of ozone to ...
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68 views

Why is platinum an excellent catalyst in comparison with similar metals? [duplicate]

What is special about platinum structure which actively participate in catalytic reactions while similar metals with similar atomic structures cannot.
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Nickel(II) + borohydride debenzylation reaction mechanism

I've been looking at this reaction for cleavage of benzyl esters. I've also looked at the original paper and some others, but haven't been able to find any mechanism on how this reagent does ...
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How does metal ions assist oxidative rancidity?

Oxidative rancidity is defined as the oxidation of unsaturated lipids and the carbon-carbon double bond with the presence of typically oxygen gas. Sometimes aldehydes and ketones are released as ...
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Type of adsorption in catalysis

why type of adsorption takes place during catalysis? It can't be physisorption because it involves formation of chemical bond. It shouldn't be chemisorption too because it is characterised by ...
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201 views

How does a catalyst accelerate both forward/reverse reactions simultaneously?

A catalyst is known to speed up both forward/backward reactions of a reversible reaction. But how does this work, because the mechanism for the forward and backward reactions could be different right? ...
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1answer
80 views

What is the significance of “magic numbers” of atoms in nanoparticles?

In gold nano particles, as the synthesis method improves to form smaller and smaller nanoparticles, they tend to congregate in magic numbers. I want to know if these magic numbers occur in other ...
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105 views

Reaction of aluminum hydroxide and nitric acid

I've been focusing a lot on aluminum hydroxide recently, or specifically breaking it down into its base components. I know that when aluminum hydroxide dissolves in nitric acid it forms aluminum ...
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Hydrodehalogenation of aryl chlorides

Palladium is the "go to" heterogeneous catalyst for dehalogenating aryl chlorides using hydrogen. What are the chemical (not economic) reasons for other precious metal catalysts not being as common or ...
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Why do catalysts have limited turnover numbers in practice?

I quote the Wikipedia page definition for Turnover number: In other chemical fields, such as organometallic catalysis, turnover number (abbreviated TON) has a different meaning: the number of ...
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Why are hydrogenation reactions exothermic?

I learnt that all reactions that yield hydrogen are endothermic (such has reforming) and reactions, that use up hydrogen, are exothermic (FCC cracking, hydrogenation, etc.). But why is this so? I know ...
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33 views

Catalytic activity of metals [duplicate]

What are the electronic features of the metals that make act as catalysts ?
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40 views

Alchohol absorbent & water repellent

Is there any solid material that is absorbent of only alcohol and not water? I am trying to look for possible ways to separate alcohol from water without the use heating and distillation process.
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Curing of polyester resin that did not reach top exothermic temperature

When working with polyester resins for fiberglass or geloat, there are times where the thickness of the resin on the substrate is not sufficient to get a strong exothermic reaction and achieving a ...
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Reasons which explain why the efficiency of a reaction increases as the average rate decreases?

Reasons which explain why the efficiency of a reaction increases as the average rate decreases? in other words, why does a slow chemical reaction is more effective than quick ones? I done an ...
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2answers
103 views

Stereochemistry of hydrogenation with Raney nickel

If I react the following with Raney nickel and $\ce{H2}$, $\hspace{65 mm}$ then I am getting a meso compound, as the $\ce{H-}$ anion will have anti addition, right? One $\ce{H}$ will attack on right ...
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Why can't Pd/C and H2 reduce both the alkene and carbonyl portions of α,β-unsaturated carbonyls?

Why is it that the major product of the reduction of chalcones the ketone and not the monoalcohol? In other words, Why isn't the major product a benzyl alcohol? From what I understand, catalytic ...
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How do copper(II) ions catalyse the reaction between iodide ions and persulfat ions?

Do copper (II) ions form dative bonds with water molecules and then a substitution reaction occurs when iodide ions and persulfate ions are added? How does copper catalyse the reaction between iodide ...
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119 views

Are Organic Solvents used in Addition Reactions catalysts?

Say for example you are performing a halogenation reaction with dichloromethane (DCM) as the solvent: ethylene + chlorine $\stackrel{DCM}\longrightarrow$ 1,2-dichloroethane I have 2 questions: Is ...
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4k views

What role does H2SO4 play in the following titration

The titration is between Oxalic acid and Potassium Permanganate, with H2SO4 added to Oxalic acid. My question is what role other than a dehydrating agent and maybe catalysing does the H2SO4 play in ...
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Why does the $V_{\mathrm{max}}$ of an enzyme not change with competitive inhibition? Shouldn't it decrease since there are fewer active sites?

My textbook states that $V_{\mathrm{max}}$ doesn't change for competitive inhibition. This makes no sense to me, since decreasing the amount of active sites available should lower the rate of an ...
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40 views

Calculation of concentration of component at catalyst surface

I am struggling a bit with an external diffusion problem. I am trying to calculate the concentration at the surface (as well as surface reaction rate) and would like some help or guidance. Here is ...
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Could the net equations for burning hexene be used as a means of energy source?

$6\ce{CO_2} + 6\ce{H_2O}\xrightarrow{some\;catalyst}9\ce O_2 + \ce{C_6H_{12}}$ $\ce{C_6H_{12}} + 6\ce O_2\to 6\ce{CO_2} + 6\ce H_2$ $6\ce H_2 + 3\ce O_2\to 6\ce{H_2O}$ At one point, I had made a ...
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Dependence of the rate of a catalysed reaction on substrate concentration?

In my answer to this question: Master equation for catalyst and substrate binding?. I made the assumption along the following lines: If we have a substrate concentration $[S]$ then the rate of ...
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How to inhibit Mn2+ autocatalysis in the oxalate-permanganate reaction?

It is well known that permanganate in acidic solution can oxidize oxalate ions (or oxalic acid). The reaction produces $\ce{Mn^2+}$, which catalyzes this very reaction. $$\ce{2MnO4^- + 16H^+ + 5C2O4^...
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Does oxygen catalyze the decomposition of sucrose?

When a bottle of sports drink that contained sucrose is opened, is it expected that the sucrose contained therein will split into its constituents (fructose and glucose) more rapidly than it will via ...
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Palladium catalyst

Recently I found the following question by sam: I'm supposed to produce dry and pure oxygen using the decomposition of hydrogen peroxide with a manganese dioxide catalyst. $$\ce{2H2O2(aq) -> ...
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Where can I find simple reaction rate formula for catalytic partial oxidation of methane? [closed]

I have already found equations here but they are too complex (heterogeneous reaction). I need a simplified (and so approximated, limited to such case, but this doesn't matter...) network of equations ...
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How might ammonia be created in this mechanochemical reaction?

Can mechanical agitation catalyze reactions? It appears so (thanks to Mithoron for the pointer!). We observed the following: We were using 10-micron hBN powder to impact-plate copper bearings (e.g., ...
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why platinum/palladium are such a good catalyst?

Platinum and palladium are great catalysts. At the same time, other metals of the same family are not. What are the atomic level reasons for this?
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Why is more of a catalyst added, when it is not consumed?

… catalysis, the acceleration of chemical reactions by substances not consumed in the reactions themselves—substances known as catalysts. (Source) Now as I’ve understood, to keep a reaction going, ...
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2answers
74 views

Effect of Catalysis on Reaction Rate in elementary Reaction

I understand that there are many different catalytic mechanisms that suggest different ways of accounting for the effect of a catalyst on reaction rate. My question is: Given a termolecular ...
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568 views

Does a catalyst increase atom economy?

Somebody I know insists that the use of a catalyst increases the atom economy. They did chemistry at school, and were told that a catalyst increases the atom economy. He pointed me to several past ...
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The Propinquity Effect

I am currently in the process of studying enzyme catalysis and am struggling to get to grips with this concept. As far as I understand, the propinquity effect allows substrates to bind with enzymes in ...
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Grubbs, Wittig & Hydroboration reactions and Woodward-Hoffmann rules

The mechanism of the olefine metathesis using Grubbs' catalyst consists of [2+2] cycloadditions and reverse cycloadditions. The Wittig reaction, too. How are they in accordance with the Woodward-...
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63 views

Basis set in the computational software “Gaussian-03” for studying adsorption of a hydrogen atom on a carbon paste electrode dropcasted with Pt-CNT

What is the basis set in the computational software "Gaussian-03" that can be used to study the interaction of $\ce{H}$-atom with $\ce{Pt-CNT}$ dropcasted electrode? How can we study the energy ...
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jury-rigging an automotive catalytic converter for use in the Ostwald Process?

Would it be feasible to jury-rig an automotive catalytic converter for use in the Ostwald Process for the production of Nitric Acid? Given reasonable safety precautions, would it be safe enough to be ...
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When an enzyme is diluted with water, what is slowing down the rate of reaction?

I'm specifically talking about the decomposition of hydrogen peroxide by bovine catalase. The number of catalase molecule obviously doesn't change, so there's the same number of catalase molecule ...
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69 views

Does the catalyst alter the Potential energy Surface?

Catalyst provides alternative pathway to the reactants. Does it also mean that the potential energy surface is altered?