hotcommodity

g'day You should memorize the strong acids and strong bases. There's only about 7 of each. When we look at an acid reacting, we take into account how strong it is. The stonger the acid, the weaker its conjugate base, and the weaker the acid, the stronger its conjugate base. If you're still stuck, tell me what you're stuck on specifically. I hope that helps.

You want to achieve a pH of 9.7 - 2.2. The question is how much HCl should be added to obtain that pH. We can find the original concentration of H3O+ by taking 10^(- orig. pH). We can also find the new concentration of H3O+ the same way by taking 10^(- new. pH). The difference in these amounts will be the amount of HCl needed for the decrease. You'll probably have to express your answer in grams or moles, so dont forget to multiply the concentration found by the amount of solution in liters. I hope that helps.

I'm assuming you know the basic trend in electron configuration is 1s1, 1s2, 2s1, 2s2, 2p1, etc... The first configuration represents the hydrogen atom, as it has 1 electron in its first electron shell. The second would be helium, as it has 2 electrons in its first shell. The next one is lithium, which has a configuration of 1s2 2s1, because it has 2 electrons in it's inner shell(n=1) and one in its outer shell(n=2). When we're dealing with ions, all we have to do is look at how many electrons were lost or gained by the atom, and subtract or add electrons accordingly, and match the electron configuration that coresponds to it. The ion may have the same electron configuration as another atom. When this happens we say that the atom and the ion are isoelectronic, that is, they have the same number of electrons. In predicting ionization, you want to keep in mind that an atom is most stable when it has 8 valence electrons. Thus Lithium wants to lose an electron to gain its octet, and fluorine want to gain an electron to achieve its octet. This idea allows us to predict charge. As for transition metals such as Zinc, its a bit trickier to predict which electrons will leave which shells. Hopefully someone else here can explain that.

I appreciate the responce, I understand it now. I was tested on it yesterday, and I was able to do 2 titrations in under an hour haha, I dont know if thats good, but it's good for me.

Think of using 2 squares, one bigger than the circle, and one smaller. How would the area of the circle relate to the area of the two squares?...

AHHH, I see what I did wrong. I really appreciate the replies, thank you

I was practicing a titration lab today that I have to do next week. I was titrating HCl with NaOH from a buret. Using an indicator to obseve the endpoint, I found that 18.32ml of NaOH was needed to react with 25ml of HCl. The concentration of the NaOH was .08045 M, and I needed to find the concentration of the HCl. Using the equation [math]M_1V_1 = M_2V_2 [/math] and converting the ml to liters, I found the final concentration of NaOH was .1277 M, and so I assumed that the HCl would be of the same concentration, but I'm supposed to get .05927 M for HCl. For M1 I have .08045 M NaOH, V1 is .0495L, what I started with, and V2 is .03118L, what I had left. I'm not sure if I'm going about the calculations wrong, or if I maybe screwed up the experiment itself. Any suggestions are appreciated.

I appreciate the above ideas, and I'll search them out. I probably should have posted this in the engineering forum, but whats done is done, lol. I was actually looking at applications of matrices to nodes in circuits, but it confused me as the examples used arbitrary voltages and the given resistances to represent the different currents. I should be ok by tomorrow, the library will be open and I can continue my research there, but again I do appreciate the direction.

That time may come very soon, lol, and I appreciate your willingness to help

I'm working on a project to show linear algebras applications in electrical circuits. I don't have alot of experience with circuits, and I don't have any experience with differential equations, so I'm not quite sure how slim my options are. Anyways, I've found out how to use augmented matrices to find loop currents, and now I've hit a wall so to speak. I've googled for ideas online but some are either too intense or not applicable. We're just starting eigenvectors, so I barely know how to work those. But if you can think of anything that I could expand on in my project given my circumstances, I would appreciate hearing them, thanks.

I assume Zn will accept an O because of how its valence electrons are ordered, but the above reaction leads me to two questions: 1) how can you predict the electron dot structure of a transition metal? and 2) would every Zn ion react with every one out of three oxygen ions, and if not, wouldnt that lead to a reversible reaction?

"How to Ace Calculus" was one of the first math books I've read outside of issued texts. I found it to be helpful as well as entertaining. Authors: Colin Adams - Joel Hass - Abigail Thompson .

Well, reactions will occur between HCl and Mg, Ca, and Al because these metals have a stronger activity than hydrogen. As for sulfur, a non-metal, it has 6 valence electrons, so it will need 2 hydrogens to fill its octet. I hope that helps, but I'm not sure what you're asking in regard to rxn's with water.

I can think of some things that are not similar between rxn's of a substance with water and rxn of a substance with an acid. Can you be more specific as to what you're looking for?

Yeah, make them bold. At least as bold as the post number on the right hand side

If someone could thicken the screen names, I think that would look much nicer.

Look in your text for an activities chart. If Zn is stronger than Ca, Zn will accpet the anion that Ca has. If not, no reaction will occur.

You need to be bant, imo

I know what you're sayin' I just think the posts blend in a bit too much with the background. I thought there were alternate skins but I dont see'em =/ Edit: I spoke too soon, seems as tho' you can have the default style too.

The site construction screwed up the LaTex, grrrr >:| HClO4 is not a weak acid. When placed in water, it completely ionizes, and never returns to its old form, just as all other strong acids do.

So... our posts are always going to laid out like this?... With the avatar over here? >>> I prefer the old style, it was more concise. But then again, maybe I'll get used to it.

Well the third law of thermodynamics tells us that when we have a substance in lattice form at ablsolute zero ( zero Kelivin), its entropy is 0 because there are no vibrations, or negligible vibrations among the ions. Anything else has a degree of disorder to it.

Don't sweat it. Understand that [math]HCl[/math] is a strong acid, and strong acids completely ionize in water. Both [math]HCl[/math] and [math]H_2O[/math] are polar, which is to say they have both strong negative and positive portions associated with each molecule. When the partial positive portion of the [math]H_2O[/math] molecules cling to the partial negative portions of the [math]HCl[/math] compound, and the partial negative portions of the [math]H_2O[/math] molecules cling to the partial positive portions of the [math]HCl[/math] compound, the[math]HCl[/math] compound is pulled apart. We know that since [math]HCl[/math] is a strong acid, it will have a weak conjugate base [math]Cl^-[/math]. That weak conjugate base is considered weak because it can't hang on to the [math]H^+[/math] ion. If you still have questions feel free to come back.

When crystal lattices are formed, they release heat, and therefore theres a negative energy value associated with the solid. All crystal lattice energy indicates is the strength of attraction within the solid. And since when does energy not exist? Feel free to expand those thoughts in the pseudoscience sub-forum.

[math]HCl[/math] will split to give [math]H^+ + Cl^-[/math] if placed into water. The fact that it completely ionizes means its conjugate base [math]Cl^-[/math] is a weaker base than the [math]H_2O[/math]. This is because the [math]H_2O[/math] is able to attract the [math]H^+[/math] ions more than the [math]Cl^-[/math] ions can. In other words, the stronger the acid, the weaker its conjugate base, and the weaker the acid, the stronger it conjugate base. Since the [math] HClO_4 [/math] you spoke of is a stong acid, it will have a weak conjugate base. If it were a weak acid, it would have a strong conjugate base. This means it will not completely ionize, and thus you'll have a reversible reaction on your hands. Conversely, the HCl placed into water will completely ionize, and the recation will not be a reversible one. I hope that helps.