Chemistry

im not sure what it is called in english, but the swedish short name for it is BTB, and maybe its the same in english, its a yellow-red liquid, that indicates pH, if you add to a acidic solution it turns yellow-red, if its added to a neutral solution it becomes green or if you add it to a alkaline solution it becomes blue. my question is, how is the chemical structure of the chemical, and what makes it change colour depending on acidic, neutral or alkaline solutions?

I found these half equations when searching for info on a lead acid accumilator, the red two was not there until I placed it, was I correct to do so? Anode: Pb(s) + SO42-(aq) → PbSO4(s) + 2e- Cathode: PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- → PbSO4(s) + 2H2O(l) Overall: Pb(s) + PbO2(s) + 2SO42-(aq) + 4H+(aq) → 2PbSO4(s) + 2H2O(l) Also, if anybody has any good links on lead acid accumulators or silver button cells I would really it, thanks.

Hi there everyone! I know that is you take say Caesium Fluoride, even though this substance actually formcs covalent bonds the difference of the electronegativity of the elements ([math]E_d = |(x_a - x_b)| = |(0.7 - 4)| = |(-3.3)| = 3.3)[/math] means that it actually has more ionic character than covalent [math](E_d > 2)[/math] and so is classed as such. My question is how would you work this out for molecules with more than two atoms / molecules bonded together? Say with something like Potassium Nitrate, would you need to work out each bond in this seperatly or is there a better way to do this? Cheers, Ryan Jones

for the hypothetical reaction aA+bB+cC→ products it is found experimentally that the reaction rate can be expressed as: Reaction rate = k[A]^α*^β*[C]^γ (k=rate constant) the order of a reaction with respect to a given reactant is the power of that reactant's concentration in the rate equation. For the hypothetical reaction just mentioned, order of reaction with respect to A = α order of reaction with respect to B = β order of reaction with respect to C = γ hmm, i've been researching and reading and all that but still i don't quite get how do u actually get α, β and γ... could anyone plzz try to explain it to me? thanx!!

All atoms of noble gases have their outermost shells completely filled with electrons. Anyone have idea?

Somethings has always confused me. It is currently assumed that the earth has a metallic iron/nickel core. The question I have is where did the reduction potential come from to make an elemental iron core when there was so much oxygen present? In other words, if one took the average composition of the earth, i.e., mostly oxygen, and heated and pressurized it, it would form a solution of sorts with the iron becoming iron oxide. To make metallic iron phase separate, one would need to add hydrogen or carbon to reduce the iron. With the earth's core 1000 times larger than the oceans, where did all the hydrogen and carbon go? Venus can support a dense atmosphere. Shouldn't the…

i'm chinese.how to use this forum very well.well.i study english 2 years.study science 4 moths.but i'm very clever(other person said that.i think i'm not clever enough)well.i skip 3 grades.only use 4 moths i study all of them about science. that's cool.but now.i'm not k.so.i study very slowly now.how to use the forums help with me study.well.my english is not good enough.so i think i need some one help me to study.i have rich imaganation on science as ainstain though i study science i only 4 moths.but i know a lot.i know the spirit of science.not study science.need rich imagination.help.aim sn is acerateactl.icq.a few time sign on it.acerateact@aim.com

how do i work out Zeff in He if i have the first ionization energy - 2372kJ/mol and the ionization energy for He+ - 5250kJ/mol. i know that IE is proportional to Zeff squared, but surely i cant work out the actual value for Zeff with only this information???? im really confused!

If a chemical reaction has an order of zero it means the reaction rate can be independant of temperature. This got me thinking and the only reactions i could think of that this was true for was radioactive decay. What I don't understand is how the rate of a chemical reaction can stay constant under different temperatures. Surely all molecules gain kinetic energy from heat so therefore all reactions are speeded up by an increase of temperature. Can someone explain this to me as i'm sure i'm missing out something really fundemental. thanks.

I have been trying to figure out these challenge problems in my Chemistry 30 class for the past week but have found no luck. here goes: molecules of NH3 are polar but molecules of BF3 aren't. SbCl3 has a measurable dipole, while SbCl5 doesn't. Explain both problems by means of atomic and molecular structures and also regarding principles of bonding.

Why are each of the following used as a reactant when testing for manganses in steel? 1) ammonium peroxydisulfate 2) Potassium periodate 3) Phosphoric acid 4) Nitric acid 5) Sodium bisulfite I am still looking through my notes and my chemistry book but struggling in the class thanks

can somone tell me if i mixing two substances is a chemical change. If so please state why, and if not please state why as well. P.S please answer asap.

Is there any liquid that is lighter than a gas?

ok im having problems with this one question out of my 50. here it is anything will help and thanks in advance thetik

Hi guys! Consider the following situation: You have 5 beakers with different salt concentration solutions: Beaker 1: 0% Beaker 2: 5% Beaker 3: 10% Beaker 4: 15% Beaker 5: 20% Which one would have the lowest freezing point? My guess would be the 20% one. Also, is there a limit to how low the freezing point can go? Does that limit mean that no matter how much of the solute you add, the freezing point won't reduce any further? Thanks alot guys!

Currently I am learning Equilirium, and when I get to the Dymanic Equilirium or rather the LeChatelier's Principle, I became confused. Well, not exactly confused, but don't fully understand the concept. I understand that whenever a system at equilibrium is subjected to a stress, then the equilibrium will shift in a direction so as to relieve that stress. And the stresses may be a change in temperature, concentration and/or pressure(volume). When either one of those stresses occurred I am having a difficulty to decide which direction the equilibrium will move. Right or Left? (Or even no change). Use this example: 2NO(g) + O2(g) <===> 2NO2(g) + energy (a)…

1.why is there a temperature change on mixing 10ml ethanol and 10ml hexane?what is the effect has been produced by the hexane on the intermolecular forces between the ethanol molecule? 2.Explain why the hexane has to be used in excess if use same amount of ethanol but 20ml of hexane?

TiO2 + C + 2Cl --> TiCl2 + CO2 then TiCl2 + Mg --> Ti + MgCl2 above is the typical way of producing titanium... however, why not just react TiO2 with C, so the reaction looks like: TiO2 + C --> Ti + CO2... wouldnt the simpler method uses much less energy?? please help

I always wonder why this happens... if I place a cup of water on the table, after a very long time, the water is gone... why's that? why doesn't it remain liquid water?

what is it? In a question it said which has the most lattice energy: K2O, MgO, KOH and NaCl. THe answer was MgO and i dont know why.

Hi there everyone! I've been reading up on electron configuration and I just don't understand it at all. I know there are 4 shell types (s, p, d, f, and a hypothetical g). But I just don't undestand how to use these. Can someone explain this to me in a simple way? e.g. I know that Hygrogen has the configuration of: 1S1, Helium: 1S2but I don't understand how you'd do these as needed in say an exam. I'm much appreciate it if someone could explain how you are supposed to work these out as needed - How am I supposed to know the configuration based on the proton number (Or the electron number because they are both the same unless its an ion...)? Thanks for the…

there was this one question about complexes. It asked which would most likely form ligands in a Co+2 complex: CO, O, or Iodide, and something else. Well, how do you determine which will most likely form the ligand or on?

Hi all, I'm new to this, but everybody needs somebody, sometime. I am a first year chemistry student and bought a ti 89, but it is not allowed for tests. Graphing calc are a no no. I need to know the best sci calc to use with the thousands of equations that are given to me to solve. thanks for the help

Hi guys, Just wondering is there a way of actually measuring the entropy value (S) of a single substance, without reacting it with something and measuring the change in entropy? P.S. My Chem teacher didn't know!!! Thanks

A gaseous binary (2 distinct elements) compound which is known to contain hydrogen (H) has a density of 1.94 times that of oxygen gas (at the same temperature and pressure). When 1.31 g of the compund is completly burned in ecxess oxygen (O2), 1.21 g of water is formed. Determine the formula of the compound. Ok...I'm pretty sure this is a combustion reaction, and that you are supposed to solve for moles using density. But how? This one is hard, I think, because it is difficult to see the relationships between the various elements.