Chemistry

Hi everyone, Can someone please help me with the above. I don't get why ammonium is positive - I mean, it has an extra H, it hasn't lost an electron. The extra electron gained from the 4th N-H bond would give it an extra electron to NH3, which should give it a negative charge? Also, how/why can it form that 4th N-H bond that takes it from NH3 with a full energy field to NH4? I'm really confused, this is questioning my basic understanding! thanks in advance everyone Gav

We've made an experiment which can be described like this: In an Erlenmeyer was put around 1.0 gram of Magnesium (Mg) and added 15.0 mL of a solution 3 mol/L of Sulfuric Acid (H2SO4). Mg + H2SO4 --> MgSO4 + H2 Then, was added Ethilic Alcohol. What happens? Is there some phenomenon? The theoric note notices that it's supposed to occur something. But it doesn't notices what.

On two occassions now following grilling nan breads our carbon monoxide monitor has gone off in the kitchen. I've checked that it isn't the gas grill on it's own that's giving of CO becuase I've just lit it and left it on for several minutes. The alarm only goes off when it's grilling nan breads!! Any ideas?

I've been experimenting with ferrofluid and reading alot about it but i couldnt find any where on the web info about ferro that does not stain glass or see- through plastic? is there such a thing? i really hope there is, if there is can anyone tell me how to make it or where to buy it?? thanks.

can we get a little amount of water when we mix hydrogen and oxygen proportionally under specific conditions?? as in the case of production of HCl???

Too risky or a great way to kit our your lab? This is what one scientists did... Any thoughts?

What would happen if you heated wood in a vacuum?

For a final project in AP chemistry we have to do a lecture demonstration. Its basically just a lab that relates to at least 3 units we have done this year, a report about it and a demonstration of it to the class. I really don't know what to do. I don't want it to be too simple like just lighting some powder on fire, but I don't want it to be too complicated or dangerous. I've seen some cool ones in videos but most of the time they don't give specific values I would need to do the experiment myself. Like this one which I think would be cool to do: http://exploscience.com/Home/Green%20Fire%20Light.wmv but I couldn't really find any info on it. I also think …

I want advice from you guys. Do any of you use a chemical catalogue for your labs? Do you use a general peice of software such as access or excel, or do you use a purpose-built peice like cispro or chemidex or something?

My son and I tried to make homemade sodium acetate with baking soda and vinegar and filtering with carbon..no luck! His project is due in 2 days and NO ONE sells sodium acetate at stores anymore! I am stuck..i want to try the homemade version again...can any one help? This is for making hot ice but we already used the Instructables version...or is there something else I can substitute ???:doh::doh::doh::doh::doh:

In a lab class, we have done the following experience: 1. In a watch glass was put some KMnO4 grains, then, some drops of concentrated sulfuric acid. 2. On the end of a glass rod, we put a piece of cotton and we wet it in Ethylic Alcohol. Final part: We leaned the cotton on the watch glass. Result: An explosion (much gas) so... I cant understand what happened, what's the function of the sulfuric acid... and what are the reactions...

Hello, I do tintype photography as it was done in the 1860's. I have recently slowed down this type of photography due to the fact that I just had a baby. I've actually only worked 2 events since his birth; he is 4 months now. Here go with my questions: 1. I know that the silver nitrate on my fingers is black because it alters to silver chloride and I know that silver chl. is toxic in granular form; but once it is stained on my fingers/hands, is it still toxic? I obviously ask this relating to holding/contact with my baby. (and yes, I wash and wash and even use brillo pad on my hands to get as much off as possible before handling him). 2. Also, what abou…

In 1 atm of pure oxygen, the solubility of O2 in water is 1.38x10^-3 mol/L at 25 degrees celcius. The mole fraction of oxygen in air is .210. If the atmospheric pressure is 1 atm, what is the solubility of oxygen in air at 25 degrees celcius?

Naphthalene, a substance present in some mothballs, has an enthalpy of vaporization of 49.4kl/mol. If the vapor pressure of naphthalene is .300mmhg at 298K, what is the temp at which the vapor pressure is 7.6x10^2mmhg?

5.) Which of the following aqueous solutions will have the lowest vapor pressure a.).50M AlCl3 b.).60M H2SO4 c.).75M Mg(NO3)2 d.)1M NaCl e.)1M C6H12O6

Carbon tetrachloride, an organic solvent, has an enthalpy of vaporization of 29.82kj/mol. If CCl4 has a normal boiling point of 3.5x10^2K, what is its vapor pressure at 273K?

Sulfur dioxide has an enthalpy of vaporization of 24.9kj/mol. At 205K, SO2 has a vapor pressure of 30.3mmhg. What is the normal boiling point temp of SO2?

Hi, can anyone help I'm calculating KM and VMax values using a standard graph and comparing results to a Lineweaver Burk Plot. My VMax from graph is 0.0286 what is my Km? My 'plot' crosses the y-axis at 34.5 and crosses the x-axis at -7.2, what are the values of VMax and KM? Thanks.

just wondering why lavender flowers supposedly make you calmer... is it even a fact yet? iv always heard it does but never heard or seen any validation or scientific evidence to prove it. and im highly intruiged

I am a first year AS chem student and missed the lesson on how to write ionic equations on a general basis...you know...the questions where they ask you to write the full equation and thenthe ionic? Well, i can not do it for the life in me! I was wondering if there is a technique you can apply to all equations to reach the ionic equation or something along those terms. PLEASE HELP....ANYBODY!!

Great demonstration of supercritical fluids by acclaimed chemistry professor Martyn Poliakoff Would be nice to have one of these machines to impress people at parties!?

just browsing round the internet and came across this: http://arxiv.org/abs/0804.3869 and http://arxivblog.com/?p=385 They might have found Unbibium-292 in a sample of thorium. and not out of a nuclear reactor either. of course the concentration is vanishingly tiny. i really hope this is for real as it would be a major find and could turn up some interesting new chemistry. any thoughts from the masses?

Does anybody know where an individual can buy diethyl ether (60-29-7), in quantities that are reasonably unlarge (not more than $50)? I know about how most vendors will only ship it out to "educational institutions" and businesses, but if you can but 80% ether as starting fluid, it seems ridiculous that nowhere is there any 90% or 95 or... you get the idea! Thanks for helping!

I've read somewhere that when you add a little magnese dioxide (easily obtained from an alkaline battery) and mix it with hydrogen peroxide it flash boils (but isn't hot ?) (low boiling point) and then a bi-product simply black staining peroxide.

Radioactive carbon, C-14, is made when a cosmic ray strikes nitrogen atoms and replaces a proton with a neutron. Thus, the rate of C-14 production is (almost completely) independent of the concentration of carbon in the atmosphere. But by burning fossil fuels which have been in the ground for long enough for the C-14 to decay, we are increasing the concentration of non-radioactive carbon, without increasing the rate of C-14. So, the relative concentration of radioactive carbon should be decreasing. Obviously, the actual amount of C-14 would be the same. Does this mean that we will be exposed to less background radiation (since our bodies would have less C-14) due to o…