Chemistry

ok, so this i cant seem to get a clean answer. So why is it that something like water having a boiling temp of 100 still evaporates at room temp? i came up with two answers and want to see if they are right 1) the pressure of the water particles is a bit more then that of 1 atm and thus slowly break free, or 2) the substance bonds with the air and slowly evaporates that way. is one of thous correct?

im trying to cast smokeless powder into a rocket motor (bates grain geometry or maybe just single grain cored geometry). i've come up with one possible solution, and im just looking for input. sugar, detergent, water, nitrocellulose powder. compact into the grain mold, and leave in a curing oven over the course of a few days at 110ish degrees. any insight or other possible solutions?

What is polarity and how is it related to chromatography?

Hi all, Well a few number of members of SFN have been confused about how to balance the equations. So I have decided to make the matter as simple as I possibly can. Consider the below equation: CH4 + O2 ---> CO2 + H2O Now assume the following: C = Yellow egg H = White egg O = Red egg. Also assuming that the reactant part of the equation (on the tail of the arrow) is Basket 1 and the product part of the equation (in direction of the arrow) is Basket 2. So the key is to balance the same number of each egg from either side (basket). You are provided with unlimited number of each coloured egg (C, H or O). Looking at the equation and fro…

Background: This pre-processed concentrate is from a mixed of oxide and sulphide ore, from a mining processing company. The readings are % per tone of concentrate. I used an NITON XLt XRF and got these readings. Nb – 0.103, Zr – 0.012, Cu – 9.38, Pb – 7.28, Zn – 0.103, Fe – 7.34, Mn – 0.070, Ti – 0.684, Ag – 0.063, Mo – 0.002, Au – 0.020, Co – 0.062, Pt – 0.075 Other materials were below readable levels. I experimented the following: COPPER 1. I mixed the concentrate with sodium chloride 1:1 ratio then heated to 644 degree Fahrenheit or 340 degree Celsius, for 2 hours. 2. I then filter it through water, but I was only…

Hi, Carbon makes 4 bonds or at least has the ability to do so. The electronic configuration of Carbon is as follows: C6 = 1s2 2s2 2p2 Now in order for carbon to make 4 bonds it needs to have exactly 4 half-filled orbitals ( 1 2s one and 3 2p ones). An electron should be promoted to the last of 2p orbital. Promotion of electron needs energy. I was wondering where the energy came from? Does the 1s orbital make bonds with 2s orbital? because bond making is exothermic and the energy released can be used to promote an electron from 2s to 2p. Any help?

Ok i have two questions. The main one is so i want to make sodium acetate, i know i need viniger and baking soda and boil it off. I know have it in a vacume helps but does any one how to speed it up else wise? i can have it in a vacume, but if there is a faster way then that can you tell me. Also on another note, my chem teacher was talking about geting dry ice to liquad co2. He will not tell me but i know it has to do with presure and you need 3atm to get it. Is there a easer way? some why i dont need to spend 100$ on a clear presure chamber, some way i can do it on the cheep? thanks so much edit sorry about the spelling cant spell

Hi, I was going through some of the exam papers when I saw that H2S (hydrogen Sulphide) has a linear shape. I wondered that when 2 of the 6 electron on sulphur bind to 2 hydogen ones to make a bond, it leaves 4 electrons on sulphur which makes it 2 lone pair. The shape the mark scheme says is linear. I was wondering does the 2 lone-pairs of electron cancel each other effect in terms of repulsion because otherwise H2S should have had a trigonal shape. help out. Thnx

Hi, I have a few questions which I need u ppl to answer. 1. Its so confusing sometimes when you read books about which orbital is filled first 3d or 4s in d-block elements. I think since 4s has lesser energy so it is filled first. Is it correct or it is only a rule when writing electronic cofiguration? 2. I have come across with 'Group IIIA' or 'IVB" what does A and B mean here? 3. This one came in one the other forums I recently joined and there was this questions. I am going to present my answer to you but I need help. So here it goes: "Given that on mole of particles is exactly 6.02 x 10^23 particles, deduce: (a)the number of electrons required to c…

I crushed Magnesium Sulfate into a fine powder, and held a flame up to it. It started drying out (despite the apparent dry nature of it) and water, from who knows where, started boiling. I was left with a very hard clump of it, almost transparent. I could get it to glow red-hot, but not catch fire, and it would cool off the instant I removed the flame. Any ideas what's going on here? My thought is that the epsom salts gained water from the atmosphere, and the heat boiled it out.

Hello everyone I've recently conducted a flame test to find out some components in salts. http://en.wikipedia.org/wiki/Flame_test Our teacher informed us that the flame test only indicate to what the positive ion in the salt could be. (These are salts with an elemental substance as positive ion) The bunsen flame will change colour because some electrons in the positive ion will reach a higher orbit for a moment, and then fall back and in the process emit light of a specific energy (frequency). My question is why this will not happen to the negative ion, I've discussed this with some friends but none have been able to give an definite answer. Thanks for…

Why does an atom tend to seek its lowest possible energy (atoms bond to achieve a lower energy state), and what does achieving lowest possible energy actually mean?

Why does the mass of magnesium increase and wood decrease when when they burn?

Hey again! I am just wondering like is there any methods to help me balance chemistry forumals. I can do the basics with the algebra formula, but with questions like:FeSO4 + K2Cr2O7 > Cl2 + CrCl3 + KCl + H2O i get dearly confused. so any methods?

If i took a piece of hard granite, heated it and placed it in a dish of cold water, would the rock crumble and experience weathering?

Hi, I was studying electrochemistry and in the text was a mention of 'adsorbtion'. I try my best to make matter as simple as possible for Juniors who approach me to ask chemistry related problems. So I came up with how best I can describe Adsorbtion to the junoirs if they approach me for it. I would like to share it with you: " If we allow a snail to walk over a tennis ball the size of a football, it would leave its traces with look like a gel like structure. We say that the gel like structure have been adsorbed over the surface of the tennis ball i.e. embeded not sunk in" Please leave your comment about how accurate this explaination is. I am open to criticis…

I am researching the necessary components to build a Rapid Protoype 3D Printer. Check out http://www.reprap.org for the open source example I am basing my project off of. I was wondering if any of you knew of a fast drying liquid that cured into a solid nearly instantly. I was thinking that perhaps there is a product that drys faster under a UV light. I'd like to spray this liquid in layers to form 3D objects. Any Ideas?

hey i have a couple of questions, why does coke remove rust and dirt from metals? (or how) why or how does baking soda remove rust and dirt from metals. Thanks. rust is FeO2 which is dissolved by acid, baking soda is not an acid so it wouldn;t remove any rust. Since coke is low in pH its consiered an acid and would disolve the rust?

Hi all, I was asked this question which made me 2 think a lot. I will share it with you and want your take on it. " Zinc and Copper are d-block elements with atomic radius measured in nanometres are 0.125 and 0.117 repectively. The data booklet I have got says that the first ionisation energy of zinc is +908 KJ/mol while copper's is +745 KJ/mol. Question is why zinc has a higher ionsation energy than copper when it size is larger than of cooper(slightly at least)" So what I have got for answer was this: Zn = [Ar] 3d10 4s2 Cu = [Ar] 3d10 4s1 Zn and Cu both have their valence electron in 4th shell and they are sheilded by equal no of electron in bo…

how harmful can sodium acetate be??? and what do you have to do to make it harmful? i need to know for a school project.

The melting point obtained by students is usually lower than the literature value. What are the reasons for this? What improvement can be made?

can some one please send me a link or give me some help?

Hi guys! Reactivity and ionization energy are in a way the opposite from each other. I mean, with the increase of the ionization energy, reactivity drops. That's why inert gases have very very low reactivity, because of their high ionization energy. But when learning at school for Group 17 elements there is a paragraph that states: "Reactivity in this group decreases starting from F to I." Ionization energy decreases when going down groups, and normally reactivity should increase. But according to that previous quote reactivity decreases with the decrease in ionization energy:eek: :eek: . Now how right is that?

Well as I'm sure most of you will know I'm more of a Physicist than a Chemist, so, please excuse the rookieness: Okay I'll cut to the chase; I intend to carry out an experiment regarding Raoult's law and its variations, i would love some pointers, I need to prove the Law and its variations i presume for A-A A-B and B-B solutions (some explanation on wtf those are might be nice too ) I presume (notice, there are lots of presumptions going on here...) that i need an Ideal solution (or 10 of them...) and maybe a few that nicely show the variations of the Law. I know that the solution should be very dilute, (but i figured, if it was too dilute i might as well just investi…

Hi guys, I was wondering what is that smell before a thunderstorm comes after dry weather. Its very distinctive here in Australia in the summer. I remember hearing someone say it was actually ozone from the lightning; i'm not very familiar with the smell of ozone. However it could be that as I've smelt it from storms that aren't actually raining much, or are only raining far away, and furthermore the smell seems to lessen once the storm has passed or it begins to rain heavily, which seems to suggest it is produced inside the cloud itself. At it's strongest it is a smell that's reminiscent of urine(!) which is why I had originally thought it could be water+organics …