Sister needs help with these 2 questions.... these are 11th grade level... i'm of no use :p
1) In what 2 ways is energy involved in a chemical change?
2) Whats the color of solutions containing copper compunds?
any help? thanks bro's!
~haz~
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Sister needs help with these 2 questions.... these are 11th grade level... i'm of no use :p
1) In what 2 ways is energy involved in a chemical change?
2) Whats the color of solutions containing copper compunds?
any help? thanks bro's!
~haz~
Chemical changes involve chemical bonding forces. For example, atomization of water involves snapping two oxygen-hydrogen bonds. Since chemical bonds are much stronger than intermolecular forces, chemical changes require (or release) far more energy than phase changes.Quote:
Originally Posted by Hazard
A chemical change either consumes or produces energy. Note that there can never be a production of new energy, it is simply lost or stolen.
Quote:
Copper
A fairly soft metal (hardness 2.5-3.0.) It is an excellent conductor of heat and electricity, and is very malleable and ductile. It has a characteristic red colour when fresh (copper-red), but tarnishes to a greenish colour (have a look at an old 1 or 2 cent coin). Copper dissolves easily in acid. Because it is such a good conductor and it is so ductile, copper is mainly used in electrical goods. The chemical symbol for copper is Cu.
1. The change of a substance into another substance, by recombination of the atoms, i.e. by the making and breaking of chemical bonds. chemical reaction takes place. Examples: Rusting of iron and the decomposition of water
2. sounds easy but i have no clue
hey this is sis, thanks a lot guys!! You really helped!
2. Copper solutions are usually browinish-red, with a rust color.
I believe they are actually blue or white.Quote:
Originally Posted by rambo
Copper solutions are generally blue...
It's a characteristic of the copper ion in a water solution...
For bragging rights, I answered both questions at 7:16 on AM, so I win. Where is my prize?
Today, 07:16 PM
Lozgod
CHEMISTRY EXPERT Join Date: Sep 2004
Location: Alltell Stadium
Posts: 5,955
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Quote:
Originally Posted by Hazard
1) In what 2 ways is energy involved in a chemical change?
2) Whats the color of solutions containing copper compunds?
any help? thanks bro's!
~haz~
1. Energy is needed to do one of 2 things. Either combine atoms to initiate a change, or break down atoms to initiate a change.
2. I don't know for sure, but I believe it is blue or white.
prize??
nevermind didn't know what you were talking about...
Hazard said you were going to paypal the winner $50. I want my money.Quote:
Originally Posted by Hazard
I dont think it is ever blue. I think it depends on the acidicity of the solution.
I have liquid copper for my salt water aquarium and guess what color it is??? ;) :scratch: :yellowconQuote:
Originally Posted by Psychotron
Meh it's been a while since chemisty im a freaking software engineer lol
I didn't care about chemistry until I made my first gear conversion. After my nolvadex crashed, it became an obsession. True story.Quote:
Originally Posted by Psychotron
1) It's been a LONG time since general chem and I have none of my chem books with me here but ..... I think they are asking for exothermic and endothermic reactions, in the former the reaction will give off energy as heat, and in the latter energy is taken to reach the Ea, or energy of activation, and so you must add heat, or energy, to the system in order to get the reaction to occur. They may be asking for the more specific terms exergonic and endergonic though.Quote:
Originally Posted by Hazard
Exothermic reaction: Dissolving sodium hydroxide in water, if you make a 50% NaOH solution w/v it will boil.
Endothermic reaction Dissolution of NH4Cl in water: if you measure the temperature it will drop. The reaction proceeds without heating because it is driven by entropy.
2) This is an easy one ... Cu(I) solutions are green, and Cu(II) solutions are blue.
Quote:
Originally Posted by Blown_SC
Correct. If you have ever given blood. You know they drop a drop of you blood into a blue solution (copper sulfate) If your blood clumps together and sinks you have enough iron in your blood.
You only win if you are RIGHT :dg:Quote:
Originally Posted by Lozgod
Just for your own edification .... Answer 1 is right enough in it's own vague way, but your wording makes me think you are making an atomic bomb ;)
Just remember that chemical bonding occurs solely in the valence electrons, and to remove an inner shell electron you need much more energetic types of radiation, such as x-rays. In chemical reactions we are mainly dealing with infra-red radiation or microwaves.
For number 2, you need to be able to make the distinction between clear and opaque, and colorless and colored. By white I assume you mean colorless, which for most transition metals is wrong. Remember for d-block elements, or transition metals, the d shell electrons are farther away from the nucleus so less energy is needed to get them in an excited state, so that means that less energetic forms of electromagnetic radiation is needed, and consequently when they fall back to their ground state they often emit radiation within the visible spectrum. (all electrons will emit radiation when excited, but electrons in p or s orbitals will absorb energy of a shorter wavelength and emit energy in a shorter wavelength, usually in the UV spectrum.
lol thanks bro for the help with my sis's chem questions..... i wish i woulda known about this baord back when iw as in HS few years ago.... you guys would ahve done all my homework LOL
BTW loz..... an atom hasn't been "fused" yet..... but like i said in that other post at AR... we are on the brink of doing it.... if you wanan dig the post up and put it here so everyone know what we're talkin about... do so.. im too lazy
Atoms have been fused before .... it's called a hydrogen bomb. Stars are also doing fusion all the time :)Quote:
Originally Posted by Hazard
I know, I know .... you are referring to controlled nuclear fusion.
LMFAO yeah....... a professor had told me that he talked with a leading scientist in the project.... it will take a heat 7 times hotter than the sun to fuse 2 atoms together..... the only thing that can contain a heat THAT hot.... is pure energy..... pure engery can't be created nor destroyed....Quote:
Originally Posted by Powrlftr
so they somehow wrapped this "heat" in pure energy.... and the scientist had said that so far... they've gotten a reaction... but he couldn't say anymore.
he said if they can successfully doit..... 1 square inch of sea water will be able to power a city for "xx" ammount of time.... i can't remember the numbers
I remember some years ago the Japanese were working on a fusion reactor. Their method was to contain the plasma with a magnetic field, they used huge torus shaped magnets. Apparently this didn't work since I heard about this 10 years ago or so.
I meant that atoms in a chain aka a molecule. Not individual atoms. I am not a good explainer, just a good understander of things and stuff.Quote:
Originally Posted by Hazard