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If we have some reactants in all types of states of matter, will that affect the formulas of the products??? If yes, why?

2007-05-27 04:31:38 · 5 answers · asked by Arielle 1 in Science & Mathematics Chemistry

5 answers

YES!!!! It does indeed matter!

If a species is a solid in the reactant state it may not react at all. If it doesn't dissolve, perhaps ions will not be available to participate in a reaction or perhaps, as one person said, there will not be enough surface area to cause a reaction.

If you take solid NaCl and mix it with solid Pb(NO3)2 nothing happens. But if you take a solution (now those reactants have aq next to them, you get a white ppt which is PbCl2.

So, under one set of circumstances, you get no products (therefore you won't write formulas) in another, you will get a product.

If you write a reaction without the states of matter it is an incomplete chemical reaction and the reader may not know or be able to understand what is going on.

Will it affect the formulas if a reaction does occur? Maybe, but it means that you, the reader, and anyone else may not be able to write ionic or net-ionic equations. You, the reader, and anyone else will not be able to determine if the reaction "did" anything!

For example

KI(aq) + Pb(NO3)2 (aq) -----> PbI2 (s) + 2KNO3(aq)

this tells the reader that the solid formed is PbI2 and it also tells the reader that K+ and NO3-1 are spectator ions that do not "do" anything

KI (aq) + NaCl (aq) ------> KCl + NaI

did anything happen? was a solid seen? How about a gas? We don't know because you didn't put phase labels on your products!

The answer is no, this is a No reaction because both KCl and NaI are aqueous species. So if we mixed KI and NaCl solutions together, we would just have a beaker of ions floating around, the species KI and NaCl are NOT FORMED. They do not exist in that way - which means that you have indeed written the wrong "formula" as those products do not exist.

- a chemistry teacher who makes their students put those phase labels on for a reason!!

2007-05-27 10:08:01 · answer #1 · answered by Anonymous · 0 0

The state of the reactants decides the rate of reaction and the rate of the reverse reactions too. Thus a compound may be stable only over some temperature range and may dissociate back to the elements from which it forms.

Examples are many organic reactions and metal hydrides. They dissociate at higher temperatures.

If both the reactants are solids, enough surface area may not be available. Generally atleast one reactant should be liquid or gas if the other is a solid to promote the reaction.

2007-05-27 11:43:29 · answer #2 · answered by Swamy 7 · 0 0

Believe it or not, but no. You still have the same reactants and and will yield the same products. The thing to remember is to notice that it is the same things, the potential for reaction is different. Depending of surface area and diffusion in air the reaction rate my be slowed down. It would probably be ideal that the reactants were in the same state as to optimize the speed at which it reacts, if not you might have to use a catalyst to speed things up a bit.

2007-05-27 11:39:51 · answer #3 · answered by actor_kyle 2 · 0 0

youll still end up with the same thing although the speed of the reaction will b different

2007-05-27 11:35:47 · answer #4 · answered by Anonymous · 0 0

No..

2007-05-27 13:15:56 · answer #5 · answered by Norrie 7 · 0 0

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