Chemical reaction Definition and 133 Threads

I was thinking about this: Let's consider a dissociation of some chemical that can run in both directions: AB\rightleftharpoons A^{+}+B^{-} Dissociated form is soluble in a solvent and undissociated form is not - it precipitates. Then the reaction proceeds to the left much faster than to the...

Hello PF! I have a very short question. We're currently doing enthalpy balances for chemical reactions in our Thermo class. We are using the simple enthalpy balance equation: \Delta H_{\textrm{Reaction}}^0 = \sum \Delta H_{\textrm{Products}}^0 - \sum \Delta H_{\textrm{Reactants}}^0 My question...

Hi all, I am really confused at how bubbles are removed in a chemical reaction. Generally it is removed by diffusion...But is there any quantitative equation for that like adhesion energy...? I want to go in this direction to quantitatively analyse the conditions that bubbles are attached or...

Hi, I wonder if you guys could help me. During the summer I used a mould spray on upvc windows which contained anionic surfactants with chlorine bleaching agents. I rinsed this off but it left a white film on the glass and so I used a household cleaner called Flash which has < 5 % Non-ionic...

While rubbing the plastic rod with the wool causes the building up of charges on both of them. 1. What chemical reaction takes place between them. 2. Does it create anions and cations? 3. Is it the transfer of free electrons (I don't think so, because generally they are bad conductor of...

Homework Statement While rubbing the plastic rod with the wool causes the building up of charges on both of them. What chemical reaction takes place between them. Does it create anions and cations? Does it create free electrons (I don't think so, because generally they are bad...

Greetings all, I have some questions regarding to chemical reaction between Silicon,Si (wafer) and chemical dissolution. FYI, I'm doing electrochemical ething to fabricate porous Si. Could anyone help me to solve this chemical reactions? 1) Si (silicon wafer) + HF (hydroflouric acid)+...

I am reading a chemistry book printed in 1805. The chemical reaction equations are written using the equality symbol = instead of the arrow →, which is used in modern times. Anyway sometimes it is still possible to see the "old fashioned" way...

Okay let's say we have water, sodium hydroxide and hydrogen chloride. What do you think is going to happen? Do you think the pH will be the same, a little higher, or a little lower? You have this reaction down here: H2O+NaOH+HCl(assuming they are equal)= H2O+OH-+Na+(positive...

Hello! What would be the substance, chemical reaction and technique, to have the highest rate of immediate mass change, back and forth, from low to high and back to low again, as many times as needed - using only homemade DIY, non dangerous materials and equipment? My intentions are to...

what types of chemical reaction does not have oxdiztion and reduction...

So let`s say that we have a chemical reaction with liquid oxygen and liquid hydrogen, but we`ve got very little hydrogen, and very much oxygen. As we pour these two liquids together they react with on another and create water. However since there was a very much bigger amount of oxygen than...

Homework Statement what is the mass of alum that can be prepared from 1.340g of Al. Homework Equations 2Al+2KOH+4H2SO4+22H2O ---> 3H2 + 2KAl(SO4)2 * 12H2O The Attempt at a Solution given Al is the limiting reagent. Find the moles of Al using n=m/M I find Al moles to be...

But can be modulated by bubbles. PLOS ONE: The Influence of Bubbles on the Perception Carbonation Bite

I was trying to solve the following exercise: Choose the option that has the pair of substances whose chemical reaction is easily perceptiple a)Br2(aq) + NaCl(aq) b) Cl2(aq) + NaI(aq) c) H2(g) + MgSO4(aq) d) Ag(c) + ZnSO4(aq) e) HCl(aq) + Cu(c) I would say if the salt was an alkali...

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...

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)...

Is there any type of software that can figure out the product of a reaction, such as organic chemistry reactions?

Homework Statement 609.5 grams of vanadium (II) oxide, VO, and 832 grams of iron(III) oxide, Fe2O3, react according to the equation, which substance(s) and how many grams of each would be in the tube after the reaction completes? 3 points Homework Equations Equation: 2 VO + 3 Fe2O3 -> 6 FeO...

Hi all, I'm looking for the energy required for a 2-step chemical reaction: CaSO4 + S2 -> CaS + 2SO2 CaS + 3CaSO4 -> 4CaO + 4SO2 This reaction is to happen around 1600 deg. F. I solved for the heat of reaction for these two reactions with the following enthalpy equation: H2=H1+∫CpdT I...

hi I'm taking GCE O levels so this might give you an idea of my level of chemistry. For a reaction like 2H2O2-->2H2O+O2 and the question tells me it has an ΔH=-98kJ/mol so does it mean that when 2 moles of hydrogen peroxide decomposes to form water and oxygen, the net amount of heat generated is...

Hi everyone! I basically understand how the materials used in the chemical reaction of a battery work but now I want to know why some batteries have different ratings of voltage. From what I've read, this depends on the materials that are used. What does it mean for some materials to do...

Homework Statement Show that processes involving rapid chemical reactions are irreversible by considering the combustion of a natural gas (e.g. methane) and air mixture in a rigid container. Homework Equations Q_{in}+W_{e,in}-W_{b}=\Delta U+\Delta KE+ \Delta PE The Attempt at a Solution I...

If we use heat and a catalyst to crack water into oxygen and hydrogen, how can the efficiency of the process ever be less than 100%? Every joule that doesn't crack open the bonds and end up in the chemical energy of the products must end up as heat, and then we're back at square one. I'm...

Also the chemical involve in the W and iodine. Thx

I’m not very well versed in chemistry so am asking for help. I’m looking for a couple of safe chemicals which combine to react (or dissolve etc.) endothermically. It doesn’t have to be an impressive reaction, it just has to be safe and not produce masses of gas (so that’s carbonate/ bicarbonate...

Copper + NaCl + H20 = >> ? Does anyone have any suggestions on what chemical reaction will occur in above example? Thanks in advance for any suggestions

Hi, wondering if you could help me. I want to find a chemical reaction that would involve: Reactant + Air (or gases present within)----Exothermic----> Harmless gas Any help would be appreciated if you knew of a chemical that I could use to react with air to produce heat and a...

Hi, I am reading about rates of reactions, and I am confused about why we multiply the rate equation of a particular product or reactant by its respective coefficient, only taking the reciprocal of it. Could someone explain to me why this is done? Is it done merely out of convenience?

If I place a glass of white vinegar on the table, and let it make contact with air, Does anyone have any suggestions on what kind of chemical reaction has between air and vinegar? Thanks in advance for any suggestions

I am working on a project that needs 2 chemicals to react and change colors. The catch is they most likely need to be or come in a powder form, non toxic, and relatively inexpensive. PLEASE HELP!

Does anyone know the experiment where distinct circular patterns appear to emerge in a liquid chemical reaction? This experiment was covered in my thermodynamics class due to its relevance of order emerging from chaos. All I remember about the experiment is that it was not believed at first for...

First of all, I'm asking here for advice since I've seen how the members of this forum answer in a mature manner (I've read some problems like mine in the forum, however, I've not contributed some). your advice is very much appreciated (please don't mind the different field of study) I've...

i've got thoughts about a series of chemical reactions that would simply keep on repeating. perhaps by time release. the thought is to use this perpetual chemical reaction to create a battery that releases the electrons then has a series of chemical reactions eventually resulting in the two...

Hi all, I'm looking for two material to produce an exothermic reaction of 180-190 C. I'd prefer the materials to be cheap in larger quantities (think mass production). Safe, other than the heat concerns. Not extremely corrosive, toxic... Easy to clean once combined. Prefer materials that...

Homework Statement If limestone (calcium carbonate) and clay (assume aluminum silicate) are mixed together and heated then the result is cement. Cement is a mixture of calcium oxide, carbon dioxide, aluminum oxide, and calcium silicate. These bags can be purchased at any building supplies...

In other words, the whole point of the reaction is not to stabilize? And then, how does entropy have anything to do with a reaction?

In order to understand some areas of chemistry I have gotten interested in, I believe it in my best interest to learn reaction equations. Like every other reality situation, there are problems. For one, my school doesn't have the ability to teach me this, secondly, online ones for me are harder...

Is anyone familiar with any chemical reactions that release both oxygen and carbon dioxide gas as products? Or any reactions where oxygen and carbon dioxide are both reactants? Thanks.

I'm trying to think of a way to take a piece of aluminum foil and chemical separate the atoms 1 by 1. I was originally thinking of trying some sort of Electrolysis type reaction by turning the Aluminum into Aluminum Oxide... though I'm still searching for the chemical reaction/method to...

Homework Statement Which of the following are true statements about the above voltaric cell and the resulting cell chemical reaction ? a) The zinc electrode is the cathode b) Zinc will be consumed before copper c) Electrons flow from the copper electrode to the zinc electrode d) The half...

Homework Statement Give the formula to show the reactants and products for the following chemical reaction. The reaction occurs in aqueous solution unless otherwise indicated. Represent substances in solution as ions if the substance is extensively ionized. Omit formulas for any ions or...

Homework Statement In the reaction between H2O2 and I-, 15 mL of 0.30M KI, 75. mL of 0.10M H2O2 and 21 mL of 0.020M Na2S2O3 were mixed in a flask containing starch and buffer and the total volume was made up to 500mL with distilled water. The solution turned blue (indicating the presence of...

I'm assuming the standard reductionist viewpoint: that chemistry is simplified quantum physics. Of the four fundamental forces in modern physics, what forces play a role in chemical reactions? Is it safe to assume it's solely electromagnetics?

Homework Statement Do anyone know the product of: NaClO+Na_2SO_3 The thing is, while searching online, I found: Na_2SO_4+NaCl While the instructor had something along the line of (and he himself isn't sure of the answer, since he is not the one who wrote it): Cl_2+Na_2SO_4+H_2O Or...

Good afternoon, The following experiment+observation is given. I look for the explanation of the observations (means: why 1. a white residuum appears and 2. why a blue fluorescence is detected). Brass consists of zinc, tin and copper, the following reaction shall analyse these...

I'm interested in oscillating chemical reaction, as Belousov-Zhabotinsky one. Does it oscillate "forever" or it relax to a macroscopical stationary state? Ll.

Homework Statement Consider the charging of a lead-acid batter at atmospheric pressure and room room temperature. 2PbSO4 +2H2O -> Pb + PbO2 + 4H+ + 2SO42- How much electrical work must be provided to produce one mole of lead? The Attempt at a Solution We're given the values of Gibbs...

how water extinguishes fire? i mean..what is the chemical reaction taking place when water combines with fire??

Homework Statement The equation for the reaction of Al and KOH solution The Attempt at a Solution Al\rightarrow + KOH\rightarrow Al(OH)+ K I seriously don't know if this is the correct equation to represent the reaction between Al and KOH solution.