Chemistry

I cant remember whether the atomic radius increases or decreases going across the Periodic Table. And if it increases or decreases going down the periodic table. Help Pls. Also, can someone explain electron affinity to me. Thanks in advance.

I have this question that I can't answer. It's for homework and I need your help. Q. The solubility product of a saturated magnesium hydroxide solution is 1.2 x 10^-11 (mol/L)^3 at 18 celsusis degree. Predict the pH of a saturated magnesium hydroxide solution at 18 celsusis degree. Please answer back as soon as possible. Thanks

is there any way i can figure out how to find the expansion ratio of a oxy-propane reaction????? is there an equation????????

Why is the radius of a positive ion always less than the radius of its neutral atom??

is the question, I'm wagering my $ on c) Because: CH3CH3 doesn't want to lose any H+ because carbocations are highly unfavorable, which would mean its most likely the weakest acid Molecule III is the strongest acid because its postively charged Oxygen is highly unfavorable, and if it loses an H it would become highly stable. Thus making it the strongest (though not necessarily strong in a technical sense) acid. I'm also guessing that Molecule II is the second strongest because the OH group can lose an H and become resonance stabilized, making its conjugate base very weak. Even though the O has a negative charge, its also highly electronegative, so i guess …

You would like to be able to physically separate different materials in a scrap recycling plant. Describe some possible method that might be used to separate materials such as polymers, aluminum alloys, and steel from one another. An optical fiber for telecommunication is made of SiO2 glass (density= 2.20 Mg/m3). How many Si atoms and how many O atoms are present per millimeter of length of a fiber 10 micrometer in diameter? Make an accurate plot of FA versus r for an Mg2+ - O2- pair. Conceder the range of r from 0.2 to 0.7 nm. Describe the quantum number for each of the 11 electrons in sodium. If the attractive force between a pair of Mg…

If one heats water under high pressure it will eventually change into its critical state. In the critical state, water can no longer define a liquid, but will become a dense fluid that occupies the same volume as liquid water. The critical state of water changes the chemical properties of water. One change is that all minerials will increase their solubility in critical water. If one adds small ions and/or acids the solubility of minerials will increase even further. If we look at the earth, water exists everywhere. Theoretically, critical water should be able to dissolve its way through the crust into the mantle of the earth. This should be driven by hydraulic…

does any one knwo any oxidisinng and reducing agents that can be found, made or accesses easily?

If you have a sample of gas - say natural gas, and lets say it only contains CH4 and C2H6, and you know the mass of it, how do you calculate the percent of each gas in the sample?

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I need help with naming binary compounds, I don't understand it. With Binary (I) Compounds Binary (II) compounds Binary (III) Compounds can someone explain to me the concept and how to name these binary compounds. thanks Hitman47.

Can a spoonful of sugar dissolve into a saturated solution of salt? Though this question consists of several words only, I couldn't figure it out.

This may sound kind of dumb, but what exactly holds things together? I know that in ionic compounds like carbonates, the ionic bonds keep the individual ions in a regular formation and when you break a block of NaCl, for example, in half you are simply breaking the ionic bonds. But what about things that aren't ionic? When you tear a piece of paper, what exactly is happening? Why can't you "put it back together" so to speak? What about plastics? When you stretch them to the point that that they rip or break, what is happening at the molecular level? What was holding the molecules together in the first place? And metals... when you have, say, a sheet of copper what…

Is there anything that is evn older than liquid Helium:confused: or isit the coolest of the cool?

My note said that heat, oxidant and fuel are essential for a fire to occur. Is it possible for a fire to happen without the presence of oxygen?

Okay, I'm trying to balance redox equations, but the half-equation method DOES NOT WORK!!!! Say, for this equation: [math] \ce{IO_3^-+I^- ->[\text{acid}]I_3^-} [/math] Okay, so for the oxidation half: [math] \ce{I^- -> I_3^-} [/math] How does one balance this?? And the reduction? [math] \ce{IO_3^- -> I_3^-} [/math] The I in IO3 is reduced, but the oxygen is oxidized. How do I get around that?? Anyhow it just doesn't work and I've stared at this question for about 6 hours still can't figure it out I'm about to eat my own hw plz help!!!

My teacher told me that the shape of H2O is V-shape because the six outhermost e- will be divide into four group, the two group with only one e- will link to 2 H atom. The two H atoms are just like the angles of the base and the O atom locate at the top of the pyramid. Then my question is, if theouthermost e- can be divided into 4 groups, will atoms inside always link in a structure like a square-based pyramid? For example, carbon, there're 4 outhermost e-, can I divide those 4 e- into 4 groups, each group has one e-, is the carbon atoms inside a diamond are always linked like a square-based pyramid? When I view the structure of diamond, it doesn't seem to be... Then what…

Fe(s) + H2SO4(aq) -> Fe(II)SO4(aq) + H2(g) how does H2 exist as positive ion?? is it a diatomic ion or as a single atom ion in the solution?? thx alot

Hi Does anyone have (Or know of) a list of the bond energies? I'm just curios, its of no real importance. I'm just thinking of doing an analysis between them - I like messing with numbers Also, does anyone happen to know what the largest bond energy value is? I've seen some big ones but I'm shure you guys can come up with better! Cheers, Ryan Jones

Hi, could anyone help me with these... ... (a). An oxide of manganese was found by gravimetric analy'sisto contain 4.995 g manganese combined with 2.909 g oxygen. Determine its empirical formula. (b) When this oxide was strongly heated, a second oxide was formed. 8.777g of this new compound contained 6.110g of manganese. Determine the empirical formula of this second oxide. © Using these empirical formulae, write an equation for the reaction involved in converting the first oxide into the second. 4. One ore of iron is iron pyrites, FeS2 (fool’s gold). What percentage of iron, by mass, does it contain? I'm tried looking for help on googe, but haven't found any. I…

How can we determine the shape of a molecule? I know electrons in a molecule should be separated as far as possible but how we can predict this?may be this involve some mathematical skills.

Hi everyone. I'm a but stuck on two questions and have no idea how to approach them as my teacher has never covered them! What amount of each substance is contained in the following: b) [math]1.00 * 10^{22}[/math] atoms of Cu 3) The mass of one molecule of a compound is [math]2.19 * 1^{-22}g[/math]. What is the molar mass of the compound? Any help appreciated Cheers, Ryan Jones Edit: Sorry for the double post - somethign wierd happened while I was posting...

Hi, I am Final Semister of Bio Chemistry. I want to enter into Software Field (Related to my Study).. Is there any Cources for Bio-Chemistry?? Can anybody help me to Find out Softwares used and how to knowledge about that? Thanks Jen

What are entropy & enthalpy ? Are they related ? If so, how ? And what is 'Gibb's free energy' ? Thnks.

Hello, You know how you go to the refrigerator and take out the bottle of ketchup and it is cold and sealed tightly? So you think a little warm water would ease it. When you turn on the tap and stick the bottle neck onto the warm water, the bottle neck cracks! Here are my questions: 1. What is the term to describe this? 2. Why does this happen? 3. Can it happen vice versa? Say I stick a very hot stick of tempering metal into the ice-cold water as opposed to room temperature water. Would it crack!?