jdurg

Heh. No problem. I have no problem helping out as long as some effort at completing the problem is shown. I was very happy to see that you were able to figure out with only a little hint. (Too often on chemistry message boards, people post their homework here without ever showing any attempt at solving it themselves. You'll never learn if you go about it that way. But you asked a legitimate question, you showed your work after a little help was given, and you came up with the right answer. THAT is what should go on).

Heh. No problem. I have no problem helping out as long as some effort at completing the problem is shown. I was very happy to see that you were able to figure out with only a little hint. (Too often on chemistry message boards, people post their homework here without ever showing any attempt at solving it themselves. You'll never learn if you go about it that way. But you asked a legitimate question, you showed your work after a little help was given, and you came up with the right answer. THAT is what should go on).

Okay. To start off, we have the Keq for the reaction which is 0.0129. We also have the concentrations of the gasses at equillibrium which will be our starting concentrations. [H2]=0.20, [i2]=0.20, [HI]=(1.76+0.50)=2.26. The initial concentration of HI is 2.26 and those of the hydrogen and iodine are 0.20 since the extra 0.5 moles is added to the system once it has reached equillibrium. Now you can set up an 'I.C.E.' chart which shows the initial concentration, the change in concentration, and the equillibrium concentration. 2HI <=> H2 + I2 2.26 0.20 0.20 (Initial Concentration) -2x +x +x (Change in Concentration) 2.26-2x 0.20+x 0.20+x (Equillibrium Concentration) So you plug the Equillibrium concentrations into your Keq equation and solve for x. So you have done it correctly and she has done it incorrectly.

Okay. To start off, we have the Keq for the reaction which is 0.0129. We also have the concentrations of the gasses at equillibrium which will be our starting concentrations. [H2]=0.20, [i2]=0.20, [HI]=(1.76+0.50)=2.26. The initial concentration of HI is 2.26 and those of the hydrogen and iodine are 0.20 since the extra 0.5 moles is added to the system once it has reached equillibrium. Now you can set up an 'I.C.E.' chart which shows the initial concentration, the change in concentration, and the equillibrium concentration. 2HI <=> H2 + I2 2.26 0.20 0.20 (Initial Concentration) -2x +x +x (Change in Concentration) 2.26-2x 0.20+x 0.20+x (Equillibrium Concentration) So you plug the Equillibrium concentrations into your Keq equation and solve for x. So you have done it correctly and she has done it incorrectly.

That sounds pretty good to me. I'll double check on that once I get a chance, but your method sounds proper.

That sounds pretty good to me. I'll double check on that once I get a chance, but your method sounds proper.

Okay. I think I can help you here. The first thing you need to do is calculate the Keq for the reaction. This is done via the following equation: Keq = (([product1]^n)([product2]^n))/([reactant]^n). So for your problem, you would have: ([i2][H2])/([HI]^2) = Keq. Now that you have the equillibrium constant, you can just add in the extra .5 mol/L of HI and calculate the new concentrations with some minimal algebra. Once you've come up with a solution, post it here and we'll let you know if you're right.

Okay. I think I can help you here. The first thing you need to do is calculate the Keq for the reaction. This is done via the following equation: Keq = (([product1]^n)([product2]^n))/([reactant]^n). So for your problem, you would have: ([i2][H2])/([HI]^2) = Keq. Now that you have the equillibrium constant, you can just add in the extra .5 mol/L of HI and calculate the new concentrations with some minimal algebra. Once you've come up with a solution, post it here and we'll let you know if you're right.

I basically think this applies to any explosives which are listed as "High Explosives" or anything which requires a license to possess. Things like the synthesis of nitrogen triiodide kind of fall in a borderline area. I.E. if you're talking about the chemical reactivity of it, or describing it in an analytical scientific sort of manner, I believe that would be kosher. But if someone makes a post saying "How can I make [insert name of explosive compound here] with easily obtainable chemicals?", I don't think that would be alright. Now if someone says "Why is [insert name of explosive compound here] so unstable or so powerful?", I think that may be ok. In terms of controlled substances, that's generally not allowed. Describing how to make diacetyl-morphine, lysergic acid diethylamide, methlyenedioxymethaphetamine, or any other amphetamine compound, is illegal in basically any country in the world. By telling someone how to go about doing that, I think this site could be held responsible for any resulting reactions, or it could draw unwanted attention. It's kind of weird how it's perfectly legal to know how to do this type of stuff, but to tell someone how to do it is kind of borderline. (I picked up on how the stuff is synthesized from my college education/experience. Toxicology class and forensics classes all went over the synthesis of these things since knowing how they are made and why they work the way they do can help when analyzing evidence).

I basically think this applies to any explosives which are listed as "High Explosives" or anything which requires a license to possess. Things like the synthesis of nitrogen triiodide kind of fall in a borderline area. I.E. if you're talking about the chemical reactivity of it, or describing it in an analytical scientific sort of manner, I believe that would be kosher. But if someone makes a post saying "How can I make [insert name of explosive compound here] with easily obtainable chemicals?", I don't think that would be alright. Now if someone says "Why is [insert name of explosive compound here] so unstable or so powerful?", I think that may be ok. In terms of controlled substances, that's generally not allowed. Describing how to make diacetyl-morphine, lysergic acid diethylamide, methlyenedioxymethaphetamine, or any other amphetamine compound, is illegal in basically any country in the world. By telling someone how to go about doing that, I think this site could be held responsible for any resulting reactions, or it could draw unwanted attention. It's kind of weird how it's perfectly legal to know how to do this type of stuff, but to tell someone how to do it is kind of borderline. (I picked up on how the stuff is synthesized from my college education/experience. Toxicology class and forensics classes all went over the synthesis of these things since knowing how they are made and why they work the way they do can help when analyzing evidence).

It's even more fun when they touch it while it's still wet and get some triiodide attached to themselves. Then as they fly away and it rapidly dries........... KAPOW! lmao.

It's even more fun when they touch it while it's still wet and get some triiodide attached to themselves. Then as they fly away and it rapidly dries........... KAPOW! lmao.

Cool. I will give some warning though. While the gold bars offered by 'auctionmaster45' are nice and cheap, there a LOT of caveats. The first is that she is apparently VERY slow in shipping. The average time seems to be about one month. The other is the shipping cost. She neglects to mention the shipping cost in the actual auction, so while the prices for the gold bars appear to be fantastic, she makes up for that with outrageous shipping prices. (I.E. 12-14 dollars in shipping). So even though you might be able to buy the gold bars a bit below their melt price, you wind up paying the actual price per the shipping cost. I am going to e-mail her and advise that she should include the shipping cost in the auction listings, and if she fails to do that I will notify E-Bay since it is against the rules to charge about five times what the actual shipping cost is. (It's borderline fraud, and illegal according to E-Bay, to make up for a low auction price by jacking up shipping). So if you are going to get the gold bars, try and find a separate auctioner. The ones I received yesterday were from acesixx (I think that's his name), and he was great in shipping and very reasonable.

Cool. I will give some warning though. While the gold bars offered by 'auctionmaster45' are nice and cheap, there a LOT of caveats. The first is that she is apparently VERY slow in shipping. The average time seems to be about one month. The other is the shipping cost. She neglects to mention the shipping cost in the actual auction, so while the prices for the gold bars appear to be fantastic, she makes up for that with outrageous shipping prices. (I.E. 12-14 dollars in shipping). So even though you might be able to buy the gold bars a bit below their melt price, you wind up paying the actual price per the shipping cost. I am going to e-mail her and advise that she should include the shipping cost in the auction listings, and if she fails to do that I will notify E-Bay since it is against the rules to charge about five times what the actual shipping cost is. (It's borderline fraud, and illegal according to E-Bay, to make up for a low auction price by jacking up shipping). So if you are going to get the gold bars, try and find a separate auctioner. The ones I received yesterday were from acesixx (I think that's his name), and he was great in shipping and very reasonable.

When I make big batches, I like to put some sugar in there so it will attract flies and bees as it's drying. It's really fun to see a big nasty hornet get blown to pieces when it gets near the pile.

When I make big batches, I like to put some sugar in there so it will attract flies and bees as it's drying. It's really fun to see a big nasty hornet get blown to pieces when it gets near the pile.

Alright. I got my 10.5 grams worth of gold in the mail today. While it's not from the same seller as my most recent purchase, the bars are exactly the same. I did a calculation on the density, and it came out to 20 grams per cubic centimeter. Since the measurements were rough and the theorectical density of gold is 19.3 g/mL, I confirm that this is indeed pure gold.

Alright. I got my 10.5 grams worth of gold in the mail today. While it's not from the same seller as my most recent purchase, the bars are exactly the same. I did a calculation on the density, and it came out to 20 grams per cubic centimeter. Since the measurements were rough and the theorectical density of gold is 19.3 g/mL, I confirm that this is indeed pure gold.

Correct. With water, the reaction is painfully slow. At room temperature, no reaction occurs at all. As you heat the water up, you'll slowly see a reaction occur as bubbles of hydrogen gas form on the surface of the magnesium. Once it reaches the boiling point of water, the reaction speeds up tremendously. Another thing that may lead to an explosion is the rapid acceleration in temperature of the water. If you take somewhat cool water and throw it onto a VERY hot surface, it will instantaneously boil off and may do so at an incredibly fast rate. This will lead to a rapid expansion of gas which is basically an explosion.

Correct. With water, the reaction is painfully slow. At room temperature, no reaction occurs at all. As you heat the water up, you'll slowly see a reaction occur as bubbles of hydrogen gas form on the surface of the magnesium. Once it reaches the boiling point of water, the reaction speeds up tremendously. Another thing that may lead to an explosion is the rapid acceleration in temperature of the water. If you take somewhat cool water and throw it onto a VERY hot surface, it will instantaneously boil off and may do so at an incredibly fast rate. This will lead to a rapid expansion of gas which is basically an explosion.

No, no, no. The high heat does not cause water to spontaneously split into hydrogen and oxygen. If you read any introductory chemistry book, they will go over the alkali and alkaline-earth metals and their reactivity with water. Magnesium metal will react with water, but only when water is in the form of steam. Mg + Steam = Mg(OH)2 + H2. When magnesium is burning, it burns at a temperature higher than the boiling point of water. As a result, the water poured on the burning magnesium immediately vaporizes into steam. The steam then reacts with the hot magnesium metal forming hydrogen gas which then ignites. It's not the high temperature that rips apart the water. It's the magnesium metal which rips apart the water.

No, no, no. The high heat does not cause water to spontaneously split into hydrogen and oxygen. If you read any introductory chemistry book, they will go over the alkali and alkaline-earth metals and their reactivity with water. Magnesium metal will react with water, but only when water is in the form of steam. Mg + Steam = Mg(OH)2 + H2. When magnesium is burning, it burns at a temperature higher than the boiling point of water. As a result, the water poured on the burning magnesium immediately vaporizes into steam. The steam then reacts with the hot magnesium metal forming hydrogen gas which then ignites. It's not the high temperature that rips apart the water. It's the magnesium metal which rips apart the water.

Ozone is not hard to make. It's just a bitch to contain since like fluorine, it wants to react with EVERYTHING.

Ozone is not hard to make. It's just a bitch to contain since like fluorine, it wants to react with EVERYTHING.

Well my friends, This is the world's strongest acid. Oddly enough, it is not corrosive at all, but in terms of acidity, it is the strongest one known to man. (Makes concentrated sulfuric acid look like vinegar).