wolfson

On a side note, we had a competition in chemistry class to see who could get water the coldest with salt and ice. The coldest we got was close to -20C. (And a guy held his finger in there for one minute for a $5 bet, and had to be treated for frostbite...) Its supposed to be around 251.05K (-22.1oC)

Yer i just used the short version (being lazy).

Barium Hydroxide yes.

When they react, they dissociate fully, ie. form new compounds. So yes the same thing. 3 Strongest bases are: NaOH, KOH, Ba(OH)2

106 = (Rn)7s2, 6d4

Yes exactly.

It was a simple mistake to make, not to worry you will have done fine in your GSCE's.

The strength of an acid is determined by its degree of dissociation. Complete dissociation of an acid molecule means that all of the H+ (hydrogen ions) are free and able to react. Hydrochloric acid (HCl) is one acid that dissociates completely in H20 and is considered one of the strongest acids. Hydrofluoric acid (HF) is often considered stronger because the fumes that it releases are very toxic and it has the ability to dissolve glass, but technically it is a weak acid because it does not dissociate as completely as HCl.

Sara* calm down you are being silly, its at the bottom of the forums use your eyes.

Albertlee i have given you the answer so use books and learn the "dynamic equilibrium" in CHEMISTRY terms not Physics, why would i be talking about physics?

The acid is a carborane based superacid, named Fackler 1st (from the person who discovered it) or a carborane anion is fine. See: http://www.chem.ucr.edu/faculty/reed/reed.html

Remember that a pH of any strong acid can go low, HF is a weak acid, HCL with a high molarity can go -2. But the strongest acid on Planet Earth is H(CB11H6Cl6), but HClO4, HCl, H2SO4, and HNO3 are also very strong.

Interestingly enough, we can make "natural gas" from biomass now by bacterial action, much as it must have been made millions of years ago when it was stored in the earth. Unfortunately, when we do this, we get two-thirds CH4 and one-third CO2 with the result that the favourable 4/1 hydrogen-carbon ratio of CH4 by itself drops to 2.7, not far from that of petroleum. Nevertheless, this method of disposing of waste biomass, if the gas is recovered and used to replace fossil fuels, is far preferable to letting the waste decompose uselessly to CH4 and CO2 vented to the air. Much of our natural gas resource as produced today contains varying amounts of CO2, which verifies the probable origin of natural gas. It is of further interest to note that methanol can be made easily from biogas and that part of the CO2 is used to produce a higher yield of methanol. (Ref:App2002)

To enable the salt solution to reach the dynamic equilibrium, where the number of freezing particles equals the number of frozen particles we must lower the temperature so that the particles attach to the ice molecules. When the particles/molecules equal each other the are said to have reached “dynamic equilibrium” The higher the molarity of salt the lower the freezing point. The solution (NaCl·2H2O) crystals and ice crystals. This heterogeneous is an eutectic mixture.

Al2Se3 + 6H2O --›3H2Se + 2Al(OH)3 Is the correct answer. Aom: It should actaully be: AL2 SE3 + 6H20 = 3H2 SE3 + 2AL(OH)3 That would give you 6 molecules of a 3 molar compund, you need 3 moles of a single.

Dangerous id say, id keep away lol.

Yes -2 or even lower they do not have a limit.

This problem seems really easy (and probably is) but I am troubled by it for some reason. I can't remember it exactly because it was on a test in my high school chem. class today. What is the pH of a solution that has 12.00 g Na(OH)2 and 250.0 mL H2O? Firstly find out the molarity: Molarity = Number of moles (n) x Volume (dm^3 or L) So: Number of moles = Atomic mass of compound / mass you have therefore n = (22.99 (Na) + 15.99 (O) + 1 (H)) = 39.98g Therefore: n = 12.00 / 39.98 = 0.300 Moles Then molarity Molarity = Number of moles (n) x Volume (dm^3 or L) therefore: M = 0.300 x 0.250 = 0.075 M. Then calculate pH for a base and REMEMBER there are two molecules of OH so: pH(Lx_n) = 0.075 x 2 = 0.15 M (new pH calculative molarity) Thus: pH(base) = Molarity / Water constant (1.0e14) pH(base) = 0.15 / 1.0e14) = 0.0000000000000015 then pH = -Log(final M) pH = -Log(0.0000000000000015 (15e-15) = 14.82 And the pH of an acid or base has an Infinite level.

Another genious, oh they are just so common, so have you a MD or are you prentending due to crank on chair been firmly up ones backside?

Would it be good to use as a online learning system?

Ok ill find out how much that one is. ty

Ty, which package on the website do you think is best MD?

No Z = X - u / sigma, not sqroot.

Well i think i might have the answer "blackboard" ive written an email to ask for some pricing and if the price is not to over the top i might be able to buy the software. So what do you think? have a look at http://www.blackboard.com and see which package you think "would suit the bill".

Opps didnt see it i appologise. Should'nt just read question. lol