A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.
The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course of action is part of the reaction mechanism. Chemical reactions are described with chemical equations, which symbolically present the starting materials, end products, and sometimes intermediate products and reaction conditions.
Chemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration. Typically, reaction rates increase with increasing temperature because there is more thermal energy available to reach the activation energy necessary for breaking bonds between atoms.
Reactions may proceed in the forward or reverse direction until they go to completion or reach equilibrium. Reactions that proceed in the forward direction to approach equilibrium are often described as spontaneous, requiring no input of free energy to go forward. Non-spontaneous reactions require input of free energy to go forward (examples include charging a battery by applying an external electrical power source, or photosynthesis driven by absorption of electromagnetic radiation in the form of sunlight).
A reaction may be classified as redox in which oxidation and reduction occur or nonredox in which there is no oxidation and reduction occurring. Most simple redox reactions may be classified as combination, decomposition, or single displacement reactions.
Different chemical reactions are used during chemical synthesis in order to obtain a desired product. In biochemistry, a consecutive series of chemical reactions (where the product of one reaction is the reactant of the next reaction) form metabolic pathways. These reactions are often catalyzed by protein enzymes. Enzymes increase the rates of biochemical reactions, so that metabolic syntheses and decompositions impossible under ordinary conditions can occur at the temperatures and concentrations present within a cell.
The general concept of a chemical reaction has been extended to reactions between entities smaller than atoms, including nuclear reactions, radioactive decays, and reactions between elementary particles, as described by quantum field theory.
I am currently in the process of re-writing an episode for a Science Fiction television series. I have two problems. A scene at a Japanese Naval Base where I need to inflict mass casualty thru a chemical reaction that will affect only the area of the naval base itself, and wipe out all the...
I'm a bit lost. I began by the cuts but then got lost: should I introduce the reactions like Ra when writing the equations? And about the force P I should introduce, should it be equal to Rc or Vc? If anyone could give me the proper plan on how to solve this problem I will be thankful. Thank you.
Homework Statement
Calculate the normal potential at 25 °C for the reaction:
HA(aq) + e- → A-(aq) + 1/2H2(g)
if the dissociation constant of HA is equal to 3.3*10-4
Homework Equations
ΔG° = -RTlnK ⇔ -ΔG°/nF = RT/(nF)lnK ⇔ E° = RT/(nF)lnK
The Attempt at a Solution
Just...
I am looking to find the reaction forces on the bottom of the rectangular shape I have included (sorry for the crude diagram). I have a moment on the top right beam (390600 lb/in) and a distributed load of 160 lb/in across the entire surface of the top of the rectangular prism. I am looking...
Homework Statement
For the two parallel reactions ##A \stackrel{k_1}{\rightarrow} B## and ##A \stackrel{k_2}{\rightarrow} C##, show that the activation energy ##E'## for the disappearance of ##A## is given in terms of activation energies ##E_1## and ##E_2## for the two paths by...
Action and reaction are equal and opposite.
So, when mass (matter) acts on space and bends it, why doesn’t space react to this action in any detectable way?
Homework Statement
can anybody explain the mechanism of the reaction
C6H12O6 +CH3COCl → CHO(CHOOCCH3)4CH2OOCCH3
glucose + acetyl chloride → glucose pentaacetate
Homework Equations
none
The Attempt at a Solution
I am thinking that the CH3COCl will split as CH3C+O and Cl-...
Homework Statement
Describe two considerations when building a nuclear reactor that would minimize the environmental impact of the nuclear fission reaction.
Homework Equations
I could think of one. is it even correct?
The Attempt at a Solution
The reaction needs to be kept in a...
Let's consider a stationary ball lying on the floor.
The weight of the ball acts downwards and the normal reaction acts upwards. They are of the same magnitude but not of the same type.
So normal reaction is the reaction to what, if not weight ?
QUESTION: Say I have the following equilibrium reaction
CO+\frac{1}{2}O_2\leftrightharpoons CO_2
The stoichiometric mixture of CO and $O_2$ in a closed vessel, initially at 1 atm and 300K, is exploded. Calculate the composition of the products of combustion at 2500K and the gas pressure.
Take...
Hi there,
How to write the reaction between water and chromium metal under standard (i) acid and (ii) base condition?
Cr + 3H2O ----> Cr(OH)3 + 3e- + 3 H+ (acid condition)
basic solution ?
Please help
If we want to be precise, should rate laws and corresponding ODEs correctly be expressed in terms of concentrations, or in terms of activities? In other words, are reaction rates really functions of concentrations, or of activities (which would make more logical sense) - and if the latter, why...
I do not understand how equation(3) occurs.(taken from the book Internal Combustion Engines by John B.Heywood)
$$ $$
Consider a reactive mixture of ideal gases. The reactant species M_a,M_b etc.and the product species M_l,M_m etc. are related by the general reaction whose stoichiometry is...
Homework Statement
A 2000kg car pushes a 1000kg garbage can at constant speed . The car exerts a force of magnitude CB on the garbage can, and the garbage can exerts a force BC on the car. Which force has greater magnitude, or are they equal? explain
Homework Equations
Fcb=-Fbc
The...
I've attached a screenshot of the internet page where the homework questions are, which shows the problem and my answers (It says I got A right, but B and C are wrong).
So I did this a few times with other tables and got the right answers, but this one is weird and the website isn't...
Given some chemical reaction, A+B -> C+D (all are ideal gases) that occures in 298K and 1 atm.
why can't I automatically say that ΔH=0 for this reaction?
I know that enthalpy is a state function that is dependant on temperature alone (for an ideal gas),
and the final and initial temperature...
Homework Statement
Balance the following equation and write the corresponding
ionic and net ionic equation (if appropriate):
CH_{3}COOH _{(aq)}+ KOH _{(aq)} \rightarrow
Homework Equations
None as far as I know.
The Attempt at a Solution
I wrote:
CH_{3}COOH _{(aq)}+ KOH...
1) K2CrO4 is produced by the reaction of FeCr2O4 with K2CO3 and O2 in a high temperature. This reaction also produces Fe2O3 and CO2.
If 169 kg FeCr2O4 reacts with 298 kg K2CO3 and 75 kg O2 and so it produces 194kg K2CrO4 then calculate the efficiency of this reaction.2) The equations is: 4...
I understand the Gibbs Free Energy equation that was drilled into us in Chemistry class but not even my teacher could explain what entropy had to do with free energy, and furthermore, why entropy is a driving force for a reaction. From what I understand, entropy is the distribution of energy...
Homework Statement
Establish K at 298K for the reaction:
2N2O4 (g) + O2 (g) → 2N2O5 (g)Homework Equations
ΔG° = -RTlnK
The Attempt at a Solution
I've established that ΔG° = 34.4 kJ/mol (Correct) but for some reason when I solve for:
K = eΔG°/-RT
K = e34.5/(-(8.314)(298)) = .98495
I get...
Homework Statement
Pt l H2 (1atm) l HBr (1x10-4M) ll CuBr l Cu = 0.599 V at 298K
i) determine the overall cell reation and calculate the Ksp of CuBr at 298K
ii) What would be the effect on EMF if pressure of H2 increases from 1atm to 2atm. Why?
Homework Equations
CuBr = Cu+ x Br-...
Homework Statement
Fermions and bosons combine through the reaction
F + F + ΔE = B
(so the creation of a single boson requires 2 fermions and some positive energy).
What is the ratio of fermions to bosons at T = 0?
Homework Equations
2[nF]/[nB] = K(T), where [nF] is the...
Hi
I want to define an Am-Be source in MCNPX 2.6
But I don't have Gamma spectra of this source.
Is there any computer code that can simulate (Alpha,Gamma) reaction?
Please Help!
Homework Statement
Determine the reaction force from water flowing through a clean 0.02cm (Diamater assumed) hole in tank depth 3m
Homework Equations
P = rho.g.h
A = Pi.R^2
P=F/A
The Attempt at a Solution
P = rho.g.h = 29400 Pa
A = Pi.R^2 = 0.00031415 m^2
P = F/A -> F = PA =...
Homework Statement
Write the equation for the esterification reaction for acetic acid and ethyl
alcohol to form ethyl acetate.
•
Circle the acid functional group and underline the acidic hydrogen.
•
Circle the alcohol functional group
•
Circle the ester functional group.
The...
Homework Statement
Which of the following combinations (in water) causes a reaction? Write a balanced reaction equation for the cases that cause reaction:
CU2+ + H2(g)
Fe2+ + AG
Fe3+ + Sn2+
etc...
Homework Equations
Not applicable.
The Attempt at a Solution
I've...
Can Anybody help to code this in matlab
A->B --- A is Sbbstrate here and B is Product
Y[b][/a]=stiochimetric
Initial values are A[0] and B[0]
Q= reaction quotient
R=active if Q<k ----- R is reaction
R=Stops if Q=k
t=...
There seems to be a problem with radiation reaction force.
Let's look at charged sphere, attached on a rod to an object with larger mass, and rotating around its centre together with it.
The rotating charged sphere emits radiation with power P.
The sphere's speed is V.
Assuming energy is...
Hi,
Im stuck: I found this example in which they calculate the rate of reaction: the title is "calculating the average reaction rate"
Now how the hell is this average reaction rate if they didnt use stoichiometric coefficients!? (in this case it should be 2.
Thanks in advance.
Homework Statement
will it have a reaction?
Homework Equations
Equation:
Pb(NO3)2 + Cu --->?
The Attempt at a Solution
Pb(NO3)2 + Cu ---> Pb(NO3)2 + Cu ------ Cu(NO3)2 + Pb
I was working on a synthetic problem involving the abiotic synthesis of amino acids (not a homework question). It has been proposed that, in early Earth conditions, DAMN (diaminomaleonitrile) catalyzes the formation of dipeptides -- in this case gly-gly. However, it has been found that only a...
Homework Statement
Number 8 is the one I was unsure of in my exam.
I know a hydride shift would give it a better carbocation, however it was not tetra hedral, so I panicked, and quickly did a alkyl shift, it worked out on the exam, but I was on the verge of running out of time so I...
Homework Statement
Can somebody help me balance this redox reaction using either the redox number method or the half equation method? Thank You
Na2S + Ag + HNO3 + Na2CrO4 ----> Ag2S + Cr(NO3)3 + NaNO3
Can you please explain your steps.
Thank YouHomework Equations
The Attempt at a Solution
I...
Burning a 3.230 g sample of the unknown compound in an excess of oxygen produces 4.7341 g of CO2 (carbon dioxide). The carbon initially in the unknown compound is completely converted to carbon in the CO2.
If it is determined that the molecular weight of the unknown compound is 180.16 g/mol...
Homework Statement
given:
2 H3PO4 + 3 Mg(OH)2 + 1427 kj → 6 H20 + Mg3(PO4)2
How much heat is involved if 927 grams of Mg(OH)2 reacts?
Homework Equations
The Attempt at a Solution
927 g x Mg(OH)2 mole/56.305g x 1427 kj/3Mg(OH)2 mole = 70,482 kj
I just felt like I...
Homework Statement
(2S,3S)-2-chloro-3-methylpentane + high concentration of CH3O- ---> ?
The Attempt at a Solution
I need to find the product and usually my method is to knock off the -Cl replacing it by
-OCH3 and when drawing the compound I just make an mirror image. In...
Homework Statement
I´ll show it with a picture:
Homework Equations
Static equilibrium, Sum Forces=0 ; Sum Moments= 0
The Attempt at a Solution
With the Fx, and Fy equations I can calculate the reactions Rx and Ry but I don´t understand the moments equation:
Sum M around...
Funny or ouch??
So you come across some modern slapstick clips like this:
for instance.
You see bloopers, people crashing in various forms into solid objects. What's your honest first reaction?
I went for 'ouch'. Can't see any humor into people getting hurt. Thoughts?
Homework Statement
In a general sense, how do you determine what the product will be in a chemical reaction? In the first example, a gas evolution, you combine the cation of each compound and pair it with the anion of the other:
HNO3(aq) + Na2CO3(aq) ----> H2CO3(aq) + NaNO3(aq)...
Hi,
Is the reaction between potassiumhydrogensulfate & potassiumhydroxide a proton-transfer reaction? If it is, it must also be an acid-base reaction. But the problem is that its not a reaction between an acid & base, but between a salt & a base!
Thanks!
Hey there PF,
I'm trying to determine the reaction equation for a little home experiment I've been conducting. The setup is very minimal: copper metal in a solution of 3% H2O2 and 5% CH3COOH. In reality, I'm probably missing something fairly straightforward.
The reaction occurs very...
Hello!
I need to find the force exerted by a sphere on an object, with the height of the object on the sphere and the object of the mass konwn.
I need to find the reaction of the spherical surface on the object.
Thanks!
In an liquid fluoride thorium reactor, how is the reaction started? My assumption would be a piece of fissile material would be somehow inserted into the fuel to introduce neutrons to the solution, but I have not found any information to show if this is how the reaction is started. If this is...
Hi,
Hydrochloric acid is the acid & water would be considered the base.
Also does this mean that if there are more H20 molecules the solution would be considered a base?
And if we have more HCl molecules than H20 this means the solution could be considered acidic?
If so is it possible...
Homework Statement
Find reaction for given. one beam 15 ft long supported at end (R1) and supported 5foot in from the ohter end (R2). 2000 lbs load is location at the very end on the beam 5foot from r2
Homework Equations
how do I determian the reactions? I know how to draw the shear...
Hello there,
I am supposed to experimentally determine (with the use of a calorimeter) the overall heat of reaction per mole of calcium metal in two cases:
1. When I mix HCL, calcium and water in that order.
2. When I mix water, calcium and HCL in that order.
In each case, I am...
Newtons third law states that there is a counter force to every force. Unfortunately this doesn't seem to work for moving point charges. The Coulomb force cancels out but
the B-Field of a moving point charge is:
\mathbf{B}=\frac{\mu_0}{4\pi}q...
hey guys
i am wondering what the difference between using Fe2O3 or FeO would be in a thermite reaction to produce aluminium oxide.
wouldn't the FeO produce a more energy since its enthalpy of formation is lower?
thanks for your answers!
Homework Statement
Is the following reaction possible? If so, by what force? Draw (one of, if applicable)the lowest order Feynman diagrams for the process.
n + n-bar --> ∏+ + ∏- + ∏0Homework Equations
N/AThe Attempt at a Solution
This process, it seems to me, should be possible. It...