Questions tagged [reaction-order]
The reaction-order tag has no usage guidance.
25
questions
0
votes
1answer
36 views
Calculate concentration of product after time passed
If I have two parallel reactions:
A --> P$1$ (k$_1$ = $0.00010$ s$^{-1}$)
A --> P$2$ (k$_2$ = $0.00050$ s$^{-1}$)
and know that the initial concentration of A is $0.0417$ M. How can I ...
0
votes
0answers
25 views
Calculating the concentration of reactants and products in parallel reactions after a time t
A substance A reacts with a solvent B to form an intermediate product IP. The reaction is bimolecular. The conc. of the solvent is constant at $12$M. IP can then react to form the two products P$1$ ...
1
vote
0answers
52 views
Determining reaction order from absorbance
A reaction is initiated in a solution which contained a dissolved component. The transmittance was measured at $\pu{240 nm}$ in a $\pu{2.54 cm}$ long cell. At $t = 0$ the transmittance was $1$. $\...
-2
votes
0answers
19 views
Why is a pseudo first order reaction also called pseudounimolecular reaction?
Molecularity is defined as the number of reacting species taking part in an elementary reaction . So for example if we take ester hydrolysis then as the concentration of acid/ alkali does not get ...
2
votes
0answers
43 views
Plotting second order reaction with different reactants
In a laser flash photolysis experiment, $\ce{C6H5NH2}$ $(C_0 = \pu{60 \mu M})$ is oxidize to its corresponding radical cations. There are three possible reaction pathways for the formation of the ...
0
votes
1answer
77 views
How do the terms in a rate law relate to effectiveness and number of collisions of reactants?
In chemical kinetics, we use rate law to find the instantaneous rate of reaction.
Let us consider a simple reaction
$$\ce{aA + bB -> products}$$
where the rate law is
$$\mathrm{rate} = k[\ce{A}]^a[\...
1
vote
0answers
41 views
How to graph a second order reaction with two different reactants
In a laser flash photolysis experiment, $\ce{C6H5NH2}$ $(C_0 = \pu{60 \mu M})$ is oxidized to the corresponding radical cation. The disappearance of radical cation is monitored spectrophotometrically ...
3
votes
1answer
73 views
First or second order reaction
I have that $100$ mM of K$_3$Fe(CN)$_6$ is dissolved in equimolar of the organic ion (which I assume is HCN). In the solution Fe(CN)$_6$$^{3-}$ reacts to form Fe(CN)$_6$$^{4-}$.
The formation of Fe(CN)...
3
votes
1answer
226 views
Is the rate of a zero order reaction always independent of the concentration of its reactants?
Consider the following reaction :
$\ce{A + B}$ $\rightarrow$ $\ce{Products}$
where order of the reaction w.r.t. $\ce{A}$ is $-1$ and order of the reaction w.r.t. $\ce{B}$ is $+1$. So, overall order of ...
4
votes
1answer
154 views
Determine reaction order and reaction rate
In a solution of $\ce{Fe^3+}$ the concentration was measured to be:
$$\begin{array}{c|c}
t/\pu{min} & \ce{[Fe^3+]}/\pu{\mu M} \\ \hline
10\ & 238\\
20 & 227\\
40\ & 206\\
60\ & ...
2
votes
1answer
65 views
Are the orders of reactants with respect to a reaction different for different starting concentrations?
If the reaction is repeated with $\pu{2 M}$ ethyl iodide the pyridine concentration decreases as shown below. Give the rate law of the reaction in terms of pyridine and ethyl iodide. Explain your ...
5
votes
4answers
781 views
Formula for rate constant for the first order reaction
My lecturer mentioned that the formula for the rate constant $k$ for the first order reaction is
$$k = \frac{2.0303}{t_{1/2}}\,\log\frac{[\ce{A}]_0}{[\ce{A}]_{t_{1/2}} - [\ce{A}]_0},\tag{1}$$
where $...
0
votes
1answer
50 views
In reaction equations, why are j and k sometimes capitalized to J and K?
From 'Leighton relationship' on Wikipedia:
through the following mechanism:[2]
($J_1$) $$\ce{NO2 + h\nu (\lambda < 420 nm) → NO + O (^3P)}$$
($k_2$) $$\ce{O (^3P) + O2 + M → O3 + M}$$
($k_3$) $$\ce{...
1
vote
1answer
257 views
Arrange in the order of their reactivity of SN2 reaction
Here in case of (1) it is more favorable towards SN1 reaction as it will create benzyl carbocation which is very stable.
(2) Here it is more favorable towards SN1 as it is first of all allyl ...
2
votes
1answer
100 views
Relationship between molecularity and the reaction order
Should the molecularity be equal or less than the reaction order?
Consider the reaction:
$$\ce{H2(g) + I2(g) → 2 HI(g)}$$
If we consider the mechanism of this multi-step reaction, the molecularity is ...
0
votes
0answers
28 views
Is order defined for a reaction which does not follow power law dependence?
As per my knowledge , order of a reaction is the sum of exponents of all the terms in rate law of the reaction
But reaction which do not follow power law dependence , for example , formation of HBr , ...
0
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0answers
40 views
Parallel reactions for one product
For me it is clear how I could solved the kinetic of a parallel reaction like this
But, how can I solve if this would be the case:
Thanks in advance!
0
votes
0answers
54 views
Is this statement valid for reactions of all orders? [duplicate]
My textbook (not an international standard) states that for the first order reactions only
The quantity of reactant remaining after $n$ half lives is
$$A_n = \frac{A_0}{2^n},$$
where $A_0$ is the ...
0
votes
2answers
75 views
Inconsistency in Elementary Bi-Molecular Reaction Rate Expressions
Assume the following bi-molecular reaction is elementary as written with rate constant $k_\mathrm{f}$:
$$\ce{A + A -> P}$$
This review, suggests to express the rate in terms of the production of ...
0
votes
0answers
34 views
Catalysts and activation energy
Do catalysts increase rate of reaction only by decreasing activation energy? Or can they affect the Arrhenius factor or reaction orders? Like if one catalyst is more effective at increasing rate of ...
0
votes
3answers
178 views
Balancing reactions algebraic method limitations [duplicate]
How do I balance this reaction using the algebraic method?
Seems that the equation can't be solved.
How do I balance such reaction and does the algebraic method has limitations and wont work for ...
4
votes
3answers
190 views
Second order reaction with different reactants
In a laser photolysis reaction $\ce{C6H5NH2}$ $(C_0 = \pu{60 µM})$ is oxidized to its radical cation. The disappearance of the cation can follow three pathways: (1) Dimerzing of the cation, (2) ...
-2
votes
1answer
89 views
Can iodine replace other halogen as well?
While reading about halogen family I encountered the reaction:
$$\ce{NaClO3 + I2 -> NaIO3 + Cl2}$$
I know that that the oxidizing tendency of halogens decreases down the group, so I think that the ...
-1
votes
1answer
826 views
Find order of reaction 2A → B + C
Derive the integrated rate expression for a reaction of type:
$$\ce{2A -> B + C}$$
I first need to determine the order of the reaction in order to find integrated rate law of that particular order....
2
votes
1answer
200 views
How is the Rate law of a reaction measured?
What is the Rate law of the reaction below?
$$\ce{4 HBr + O2 -> 2 H2O + 2 Br2}$$
How do we approach finding the rate law of a reaction? Can this be found out only through experiments?
