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.
What would happen to a molecule adsorbed on a flat and defect-free potential surface? Would it just stay there? Or would it go somewhere?...I see it very difficult for the reaction to occur as no preferential path is present but this is just an intuition. Does anyone have an opinion/the answer?
Scenario: Suppose that a pump creates a partial vacuum, which is used to input air (gas) from the environment into a long tube. At a certain point within this tube, diatomic hydrogen and oxygen (gases) are also inputted into the tube. The tube outputs back into the environment. I have...
I wasn't sure whether to put this in Aerospace, but decided on physics in the end.
1.) How do you factor a chemical reaction into the solution for the Navier Stokes equations? More precisely, how can you include the affects of a heat absorbing (endothermic), or heat releasing (exothermic)...
heey i have this chem homework quest :
5 L flask is filled with 0.625 mol of (N2O4) if you know that concentration of (N2O4) at equilibrium = 0.075 M
what is the kc for the rxn ??
2 NO2 → N2O4
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Ok the question is some what simple and difficult. I know there are certain rules like
a. A + B = AB (combination)
b. AB = A + B (decomposition)
c. AB + C = CB + A (substitution)
d. AB + CD = AD + CB (metathesis)
now the trouble i have is not in balancing the equation but figuring out...
[SOLVED] Chemical Reaction between water and chlorine
Homework Statement
Whats the reaction between chlorine and waterHomework Equations
NoneThe Attempt at a Solution
Is it the reversible reaction:
Cl2(g) + H2O(l) <----> HCl(aq) + HClO(aq)
Pls solve my problem quickly as i am junior, i am not expert in solving these:
SiO2 + Na2CO3=Na2SiO3 +CO2
So how do CO2 get separated from products,and where did the 1 oxygen atom go, Is this equation needed to be balanced.
Why is helium placed in the group of noble gases? Do it reacts...
Homework Statement
What are q and w (in kJ) for the reaction of 22 g of Na(s) and 82 g of Cl2(g) to produce NaCl at 1 atm and 298 K.
Homework Equations
w=-delta(n(g))* R*T where delta(n(g)) = the moles of gas created during the reaction
The Attempt at a Solution
First, I wrote...
If you light a match to a mixture of oxygen and hydrogen which then reacts explosively to form water. Is it a chemical or nuclear reaction?
I know a chemical reaction is one in which a substance is changed into one or more new substances.
A nuclear reaction is one in which a new element...
I have a problem.. for a reaction
A + B --> C
how do i generate 3 coupled differential equations so that i can sole this using MATLAB ?
it is given that rate = kAB
thnks!
I have trouble trying to figure out what happens to this reaction:
NaOH(s)+H2O(l)->
my first thought was that maybe nothing happened but then moved on to wondering wether it ionizes. can someone explain to me what happens and maybe why it does?
I was wondering if someone could tell me the chemical reaction of Baking Soda during electrolysis. According to wikapedia baking soda is sodium bicarbonate witht he formula NaHCO3. And/or could someone explain how i could figure out te chemical reaction of different items during electrolysis...
I am confuse here.Here is another question from my test.
Which of the following is a chemical reaction?
I.A piece of gold is being heated to melt it
II.A ball is being blown
III.A piece of paper is burnt
IV.A piece of sodium is out into a beaker of water
A.I and II
B.III and IV...
We lit a piece of Mg so the formula is:
2Mg(s) + O2(g) HEAT-- 2MgO(s)
We then dissolved this in water so it would then be:
MgO(s) + H2O(l) -- Mg(OH)2(l)
Next we blew into the solution which made it:
CO2(g) + H2O(l) -- H2CO3(l)
Is this all correct? Should I have (Aq) after the...
Here is my first question.
Cl2O + H2O ------->
I am pretty sure this is a synthesis reaction becasue it there is non metal oxide and a water. I also know a non metal oxide plus a water forms an acid. I predict this to be HClO3.
If that is the correct answer, I can't seem to balance...
CuSO4(aq) + Fe(s) --> FeSO4(aq) + Cu(s)
FeSO4(aq) + Cu(s) --> CuSO4(aq) + Fe(s)
http://img106.imageshack.us/img106/6140/chem3fp.png
Why does the iron plate becomes brown?
I have no precise idea, but I think it might be related to the loss of electrons of the iron plate. Could someone...
hi.
i am not chemist, and i am looking for some simple reactions which can happen at room temperature and it creates cooling after reaction, i.e. it absorbs energy.
any body know some examples? :confused:
thanks.
Hey guys could you tell me if I got the right answer; my teacher hasn't went over this material and it is due tomorrow.
Given the following reaction, how many grams of Zn are required to obtain 2.00g of Au?
4CN^{-1}~+~3Zn~+~2Au(CN)_4^{-1}~~-->~3Zn(CN)_4^{-2}~+~2Au
(2.00g of Au)(1 mole...
Hi,
Is it possible for a substance found in tobacco to cause a delayed chemical reaction that would trigger a feeling of fear and anxiety or alternativly trigger the flight or fight response ?
Thanks
Ian
Chemical reaction: Cu(s)+2H+(aq)----> Cu2+ (aq) + H2 (g)
Cu(s)+2H+(aq)----> Cu2+ (aq) + H2 (g)
Do we have this reaction?
If yes, is it a displacement reaction?
If no, is something about the oxiding power of particles?
Could you explain it to me ?
Best regards
2 H atoms can form a H2 molecule, releasing energy of 5 eV. However, no chemical reaction occurs when 2 isolated H atmos collide! Explain this curious result using the conservation laws.
first of all, i don't know what conservation law to use for this question.
2nd i think i don't have much...
Hi
I got a couple of questions regarding the following chemical reaction.
First some calculations:
90,0 \textrm{mL of} \ 0,250 \ \textrm{M} \ BaCl_{2} is mixed with 0,500 \textrm{M} of Na_{2} CO_{3} which generats residuum.
a) BaCl_{2} \rightarrow Ba^{2+} + 2Cl_{2}^{-} \ (i)...
Hi
I got a question regarding chemical reaction:
3 H2O + 2(CaSO4 . 1/2 H2O) ----> 2 (CaSO4 . 2H20)
calciumsulfat dihydrat reacting via water.
My question is:
If I have 1 Kilogram of calciumsulfat dihydrat how much water is needed ?
Thanks in advance.
Sincerely
Fred
hi,
could some one please verify what i have done here or tell me where i went wrong.
suppose the activation energy for a chemical reaction is E*, i have to work out how the rate of the forward reaction depends on temperature T and concentration. (note: i am given the Boltzmann distribution...
I've always wondered if our feelings have something more deeper then a simple chemical being released in our brain or chemical reaction taking place in our body. Are feelings of love and happiness simply a matter of how much seritonine we have, how much dopamine we release.. etc? Is there...