The study of rates and steps (mechanisms) of chemical processes.

learn more… | top users | synonyms

2
votes
1answer
26 views

How the equation that describes evolution of alkyl nitrates has been derived?

I was reading this paper, Bertman, S. B., J. M. Roberts, D. D. Parrish, M. P. Buhr, P. D. Goldan, W. C. Kuster, F. C. Fehsenfeld, S. A. Montzka, and H. Westberg (1995), Evolution of alkyl nitrates ...
0
votes
0answers
14 views

Solve system of rate equations with SciPy odeint

The image below illustrates the kinetic scheme I am trying to model. My first example focuses on the conversion of the wood-oil to non-volatiles and volatiles. The rate equations are as follows: ...
0
votes
0answers
8 views

What is the reaction order for a bicarbonate neutralisation reaction?

I have been assigned to investigate the rate of reaction between sulfuric acid and sodium bicarbonate solution by conducting a typical rate of reaction experiment involving water displacement method. ...
-1
votes
0answers
10 views

Chemical Kinetics Question with pressure [on hold]

This is the question ttp://i.stack.imgur.com/PXPLZ.jpg And here is the solution The problem is I am not sure if my answer is correct Can anyone help me in verifying it
0
votes
0answers
8 views

Mechanism of thyroid hormone synthesis: iodation and free radical formation

In the synthesis of thyroid hormone, what part of the thyroid peroxidase hormone is specifically responsible for abstracting the free radicals from the aromatic side chains in the iodated tyrosine ...
-3
votes
0answers
16 views

Chemical kinetics and pressure[FORMULA] [on hold]

When I was flipping through a physical chemistry book I found a formula which looked like To be frank i dont know what it is about,apart from the fact it deal with pressure and rates Can someone ...
0
votes
0answers
20 views

Is there are any universal methods or software for reaction rate modelling?

In software like DWSIM are used databanks which contains enthalpy and entropy at 298 K and more other information about chemicals. This software can create a steady-state system, where showed state of ...
0
votes
0answers
22 views

A rate problem;Determining the order

My attempt I believe the answer should be second order reaction looking at the units of k But I think the question is to be solved with the help of integrated laws I tried using it to check ...
-1
votes
1answer
17 views

Rate problem: Determining the order

In the presence of an acid, the initial concentration of cane sugar was reduced from 0.20 to 0.10 molar in 5 hours and from 0.2 to 0.05 molar in 10 hours. What is the order of the reaction My attempt ...
3
votes
1answer
82 views

Problem on chemical kinetics

Is the question asking the concentration when the system has reached its half life Can use the half life formula? The attempt at a solution I used the rate law which I equated to the definition of ...
0
votes
1answer
46 views

Calculating time taken for a set percentage of a reaction to occur based on half-life

The half-life of a first order homogenous gaseous reaction: $\ce{SO2Cl2 -> SO2 + Cl2}$ is 8.0 minutes. How long will it take for the concentration of $\ce{SO2Cl2}$ to be reduced to 1% of the ...
0
votes
0answers
24 views

Latent Heat and Kinetic Energy

The kinetic theory says that temperature is the measure of the average kinetic energy. That would mean then : The temperature rises with the rise in kinetic energy. We know that when matter changes ...
0
votes
0answers
33 views

Elementary Reactions

I'm studying some kinetics of reactions and in particular the topic analyzed is the bromidic acid production starting from $\ce{H2}$ and $\ce{Br2}$. The reaction $$\ce{H2 + Br2 -> 2HBr}$$ can be ...
0
votes
1answer
22 views

Does the Hydrogen/Chlorine reaction in light proceed instantaneously?

When a mixture of Hydrogen and Chlorine is exposed to short wavelength light it reacts explosively. Does the reaction happen simultaneously through the bulk of the mixture?
0
votes
0answers
25 views

potential profile in kinetics and spontaneity in reactions

We usually think of the criterion of spontaneity of a reaction as the change of Gibbs energy. By Clausius inequality, one of various forms of the 2nd law, we know that $ ...
2
votes
1answer
38 views

Deriving kinetic equations for a complex reaction system

I have a system of protein reactions that I've derived differential equations for the kinetics of. I'm using them to run simulations to fit the rate parameters, but the simulations at present are ...
3
votes
1answer
57 views

The effect of reactant concentration on when equilibrium is established

Take the equation $$\ce{A(g) <=> B(g)}$$ where the reaction is first order with respect to A. The rate law is thus $$\frac{\mathrm d[\ce{A}]}{\mathrm dt}=-k[\ce{A}]$$ Say you run the reaction, ...
1
vote
0answers
13 views

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 ...
0
votes
1answer
42 views

How does changing the concentrations of intermediate products/reactants change the rate law?

A = CH2(CN)2 B = CH(CN)2- C = BrCH(CN)2 The rate law above is derived from applying the steady state approximation. I am trying to work out how to modify the rate law to accomodate the following ...
0
votes
0answers
16 views

Factoring in kinetic equations [duplicate]

The mechanism for the linear chain reaction of H2+Br2 -> HBr is: If we presume steady state for the chain carrier Br*, we recieve this equation: My question is in regards to the '2' factor marked ...
1
vote
0answers
17 views

In Statistical Transition State Theory, why is $[AB^{\ddagger}_f] = [AB^{\ddagger}_r]$?

For example on Wikipedia (https://en.wikipedia.org/wiki/Transition_state_theory), and also in my lecture notes, it is assumed that for a reaction $A+B\rightleftharpoons AB^{\ddagger} ...
0
votes
0answers
24 views

How can we integrate Maxwell-Boltzmann's distribution to obtain the expression for activation energy?

I tried integrating the expression first by replacing the v^2 terms by E. It turned out to be the integral of (sqrt.E * e^(-E/kT)). I tried integrating it by parts but the exponential term will ...
0
votes
0answers
36 views

“Reacts most vigorously”

What is meaning of "Reacts most Vigorously" Is it related to Thermodynamic aspect or Kinetic? Like for example if we are given that A reacts with C more vigorously than B reacts with C. Then which ...
0
votes
1answer
27 views

Which reactions are more temperature sensitive, the ones with higher Ea or the ones with lower Ea and why?

I wasn't able to find much useful content on googling it, however on doing the math i came to a conclusion that the ones with higher Ea are more sensitive to increase in temperature. But why is it so? ...
0
votes
0answers
16 views

Halving the electrolyte concentrations of a voltaic cell

Say you have a standard voltaic cell with $Q=1$. The concentrations of both the electrolytes are at 1.0 M. If you halve the concentrations in both to 0.5 M, $Q$ still equals 1 and ...
7
votes
2answers
83 views

Is the rate determining step the step with the largest Ea?

I've seen some controversy on this question while doing a brief search. For example, this SE answer quotes Wikipedia and says that the RDS is the step with the largest $E_a$. However, this UC Davis ...
2
votes
0answers
20 views

Looking for solubility kinetics of zinc chloride hydroxide monohydrate

$\ce{Zn5(OH)8Cl2·H2O}$ is a crystalline solid insoluble in water. Often used as nutritional supplement. Preparation and chemistry of zinc chloride hydroxide monohydrate is known. I am looking for some ...
4
votes
2answers
360 views

How does an energy input actually change a molecule?

I'm reading an online biochemistry textbook for fun, and a question that has bothered me on chemistry before popped up again. The question here is not specific for the chemical process described, but ...
1
vote
1answer
41 views

Experimentally finding order of a reaction

For the reaction of bromocresol green and bleach, I was supposed to conduct an experiment to find the order of the reaction with respect to bleach. To do this, I used a fixed amount of bromocresol ...
2
votes
0answers
20 views

Binding Energy and Enzyme Rate

I was preparing for the Canadian Chemistry Olympiad and I ran into the following question on one of the past exams: If enzyme A binds to the substrate 25 times stronger than enzyme B, what is the ...
0
votes
0answers
9 views

How to calculate the rate of micelle formation in a soap solution?

How can I design and conduct an experiment to calculate the rate of micelle formation in a soap solution? This would relate to the topic of chemical kinetics which we are currently doing in class.
1
vote
1answer
90 views

What does a fractional order of reaction mean for the mechanism?

I'm doing a high school/sixth form college investigation of the kinetics between magnesium ribbon and hydrochloric acid. I have obtained a rate order was 1.5 w.r.t [H+] and hence the rate equation ...
0
votes
0answers
13 views

kinetics of adsorption of hydrogen on nickel

What is the order of reaction involving adsorption of Hydrogen on Nickel? The reaction does not depend on the concentration of hydrogen (does it?) but depends on the surface area of nickel. More the ...
1
vote
0answers
80 views

Why is 2H2O2 -> 2H2O + O2 a first order reaction?

My book says that the reaction $\ce{2H_2O_2 -> 2H_2O + O_2}$ is a first order reaction and that it's rate equation is $\ce{k[H_2O_2][I^{-}]}$. However i don't see why that would be first order? ...
3
votes
0answers
16 views

Measuring reaction rates when reactants and products both have (different) molar extinctions at the chosen wavelenghth

In my Biochem labs we would always measure the consumption of NADH, and they always noted that it was useful that NAD+ had essentially no absorbance at 340 nm, which allowed us to directly relate ...
1
vote
1answer
26 views

Bimolecular and Isomerization reactions

Is it possible to describe a reaction of the $$\ce{A + B <=> AB}$$ exactly using the solution of an isomerization reaction? $$\ce{A <=> B}$$ I just can not figure it out the equations ...
2
votes
1answer
45 views

How to calculate the rate of reaction of Sodium and Chlorine

$$\ce{2Na(s) + Cl2(g) -> 2NaCl(s)}$$ How exactly do you calculate the reaction rate of the following equation? Since reaction rate is usually calculated in moles per $\rm dm^3$ per second ...
4
votes
2answers
74 views

Factors affecting mass of a gas-evolving reaction mixture over time

Excess magnesium was added to a beaker of aqueous hydrochloric acid on a balance. A graph of the mass of the beaker and contents was plotted against time (line 1). What change in the experiment ...
2
votes
0answers
56 views

Questions about Collision Theory [closed]

The collision theory states that, for a reaction to occur, particles must collide with each other. How about a reaction that has only 1 reactant, for instance decomposition of water / hydrogen ...
1
vote
0answers
24 views

Kinetics: Rate and Order of Reaction

I have run a reaction of 0.020M $\small\ce{FeCl3}$ and 0.020M $\small\ce{KI}$. The solvent of $\small\ce{FeCl3}$ was $\small\ce{HCl}$, but had no effect on the reaction and, therefore, has a reaction ...
0
votes
1answer
27 views

finding the concentration of B

At the intersection point of two curves nA-->mB, the concentration of B can be given as:(assume the reaction to be 1st order) can someone explain me how to go about it? I have no clue how to go ...
1
vote
1answer
30 views

Do we use activities or concentrations in the rate expression?

The equilibrium constant of a reaction is a dimensionless quantity due to the fact that we use activities instead of concentrations(in moles/liter). But, in the rate expression for a reaction, do we ...
2
votes
0answers
25 views

Shape of the blood CO2 dissociation curve

What equation determines the shape of the blood $\ce{CO2}$ dissociation curve? I know that since it factors all possible forms of $\ce{CO2}$ carriage, there are a bunch of factors (e.g. Henry's law, ...
3
votes
0answers
23 views

Arterial blood CO2 content, division and partial pressure

My lecturer cites Boron and Boulpaep's Medical Physiology (2nd edition) for the following claims: the total $\ce{CO2}$ content of arterial blood is $26.4$ mmol/L or $48\%$ v/v (not sure if these ...
1
vote
0answers
26 views

Theoretical Value of Activation Energy of Potassium Iodate and Sodium Bisulfite?

I investigated the Arrhenius equation using the reaction between potassium iodate (containing the IO3- iodate ion) and sodium bisulfite (containing the HSO3- hydrogen sulfite ion. The ionic equations ...
1
vote
1answer
42 views

Determine rate equations for entire kinetic scheme

I am working with the following kinetic scheme that represents pyrolysis of a biomass particle: The paper that discusses this scheme provides the following rate constants: K1 for the pathway of ...
0
votes
1answer
47 views

Comparison of rate of reaction in bromination and chlorination

I did research, about this one but the data and other things prove chlorination is faster than bromination, because chlorine is more reactive. But, some data says reaction of chlorine is more ...
3
votes
2answers
75 views

Kinetic isotope effect in nitration of benzene

What is the effect of changing all the hydrogen atoms in benzene to deuterium? For example, which of the following reactions occurs at a faster rate?
2
votes
1answer
125 views

Determine reaction rate from reaction time?

These are the results of my experiment (solution A and B were reacted and the reaction time was measured). Data Table Edit: How would I determine the rate of reaction (so I can find the rate law) ...
0
votes
0answers
28 views

Zinc oxide reduction in ethanol

I'm trying to prepare a ZnO thin film deposited on a glass substrate. The precursor solution prepared by sol gel process through dissolving 1 M zinc acetate dehydrate (ZAH) in ethanol with ...