encipher

I apologize if I'm being picky, but you CANNOT say stuff like: "the mass of anhydrous Cu(II)SO4 would increase" "change the mass of H2O, making to higher" etc.. You don't make the mass increase, not does the mass of the H2O increase. A good way to state questions like these is this way: If the Copper(II) Sulfate was not completely dehydrated of H2O, The measured mass of the apparent anhydrous Copper (II) Sulfate would be slightly higher than It's actual value. Therefore causing ...... This is just a quick example.. think up of something to write. Hopefully you got the idea.. People who grade exams and tests are very picky when it comes to wording. Hope this helped.

Sounds like a chemistry lab at school =D Your answer is somewhat right. I remember when I took AP chemistry, they stressed on clarifying my statements. First of all, the compound does not evaporate. Only the water does. A better word to use instead of compound would be salt, becuase you might forget to say 'ionic' before it and you would lose points. Again, the salt itself does NOT evaporate, only the water. If you did not heat the hydrated salt enough you would end up with excess water, giving you a larger mass at the end which means a smaller difference (betwen hydrated and dehydrated) in turn, giving you LESS grams of water, which turns out to be less moles. End result: Less moles of water. (Personally, I hated questions like these, always got me confused :S )

to get the number of water molecules to copper (II) sulfate you do this: Molar mass of CuSO4 is 159.62 g/mol Molar mass of H2O is 18 g/mol now there is 5.4 grams of dehydrated CuSO4 (5.4 grams) / (159.62 g/mol) = .034 moles of CuSO4 then for water (3.2 grams) / (18 g/mol) = .17 moles of H2O Next to get the number of water molecules to copper (II) Sulfate you divide the moles of water by the moles of copper (II) sulfate: .17 / .034 = 5 Therefore, there are 5 moles of Water for every one mole of Copper(II) Sulfate.

I beleive the reaction would be as follows: CuSO4 • 5H2O <--> CuSO4 + 5H2O (<---> is a double headed arrow (equilibrium sign) and i guess to represent the heat a triangle on top) for percent mass you subtract the weight of the beaker from the weight of the beaker with salt. 173.9g - 165.3g = 8.6 grams of hydrated Cu(II)SO4 then get the mass of the dehydrated Cu(II)SO4 170.7g - 165.3g = 5.4 grams. 8.6g - 5.4g = 3.2 grams of H2O for percent by mass: (3.2 / 8.6) x 100 = 37.2 % water

A good alloy that is both non-toxic and has a low melting point is Field's metal. It melts at around 62 degrees Celcius and contains bismuth, indium, and tin. I don't know about pricing though.. i recall buying like a foot of that stuff for 40 bucks. Not too cheap.. something a bit cheaper would be bismuth.. although its melting point isnt that of room temperature (272 degrees celcius) you can still melt it over your stove and you can do some pretty cool stuff with it. Make crystals of it etc..

Well, Because you are using time to determine concentration, then you will have to use the integrated rate law. For a first order reaction, the formula is as follows: ln[A] = -kt + ln[A]0 I'd say consider using the formula in terms of percenage. Lets assume the initial molarity is 1M. Graph the equation in terms of [A]. In that case: [A] = e^(-kt) x [A]0 (That is e to the power of negative k times t all multiplied by the initial concentration of one molar.) of course substitute X for t in the equation when graphing. Next find the point in time which you want.. then setup a ratio and find out the percentage left using regular math... hope this helps !

My reply is a bit late regarding the strongest acids. Aside from the Carborane acids (which are the strongest and least corrosive acids known to man) the strongest acide is a mixture between two compounds, Antimony pentaflouride and Hydroflouric acid. It is 20 quintillion times stronger than 100% conc. sulfuric acid. And its not a toy! It can eat right through your bones.. nothing for an average person to mess around with.