Help with chemistry basics...

Okay, can anyone tell me how to:

a) determine whether any given compound is either Gas (g), Liquid (l), Solid (s), or Aqueous (aq)?
b) determine when given 2 reactants (compound A) + (compound B), what products will be? Oh, and it doesn't have to be a compound, could be elements too.

I am so confused...


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These things you tend to either just know (eg water is liquid, at rtp [room temperature and pressure]) or you have to look up :)

okay well, first you have to understand that a liquid is a pure substance in liquid sate ie: water a gas is well a gas a solid is a solid compound or element and an (aq) solution is when you have a solute disolved in a solvent. So say you had salt water it would be NaCl(aq) instead of NaCl(s) because it is in water and it is soluable in water. To deteremine the products of a reaction you must know what type of reaction is taking place double replacement, redox, single replacement etc. Now from there you can see where the elements are going to move but you do not know what state of matter they are going to be in so if there was water involved (there usualy is) use a solubility chart to see if the product is soluable thus (aq) or insuluable thus a percipitate of the reaction and a (s). Now if it was just an element look at the periodic table and see what state of matter it usualy is in at room temperature. If you are dealing with something at a different temperature or pressure you need to do some more research.

I am not sure if people

I am not sure if people should be taking chem advice from someone that spells as poorly as you...

I will try to apply what you said to my work and see if I can solve these equations. Problem is, my homework doesn't say what type of reations are taking place. It just says to "write net ionic equations for the reactions that may occure when each of the following pairs is mixed:" Then it starts listing the problems. For example:

a) H2SO4(aq) and BaCL2 -->

and that's all I have to work with.

Then, the next set of problems says "based on the reactivity series, what is the outcome of each of the following reactions:". Then it lists problems. For example:

a) Al(s) + NiCL2 -->

Can you help me?

With # 1 H2SO4 is soluble so you get ions (parts of compounds) 2H+ and SO4-2 floating in water; if you added Sr(NO3)2, you would be adding Sr+2 and 2NO3- to the solution. Now SrSO4 joins together and is insoluble so it sinks to the bottom and leaves 2 HNO3 in solution. If you added NaCl (salt) you would get Na+ and Cl-, but Na2SO4 is soluble so you get a solution with Na-, 2H+, Cl- and SO4-2; now with BaCl you would have 2H+ SO4-2, Ba+2 and 2 Cl-2; check to see if BaSO4 is insoluble or if HCl is. If either is, it settles to the bottom and you have a reaction; if they are not, everything is left in solution. [In fact, everything has a point at which it cannot remain in solution; when the lake that once was Death Valley started drying up, certain compounds were less soluble than others and so settled out in mass, resulting in the great deposits of borax and colemanite in the region. This technique, called fractional crystalization, was used by the Curies to discover radium and polonium]

With #2) more reactive metals displace less reactive metals; Ag is less reactive that Cu, so if you have AgNO3 solution and put pure Cu metal into it, crystals of Ag with come out and a blue solution of CuNO3 is formed. So look up Ni and Al; if Ni is more reactive, it is already in solutions and nothing happens; if Al is more reactive, it will displace the Ni and go into solution.

Hope that helps

Thanks that is helpful!

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