posted by lyne .
NaCl + CuSO4
to write the product would i just do double replacement to get
Na2SO4 + CuCl2
so the whole thing would be
2NaCl + CuSO4 --> Na2SO4 + CuCl2
Yes, the reaction, if it occurred, is a double replacement and you have written it correctly and balanced it. HOWEVER, it will not react and you should have written it like this.
NaCl + CuCO4 ==> No reaction or as NR.
Reactions occur for one of four reasons.
1. a gas is formed. Neither of the products is a gas so this one is out.
2. a precipitate is formed. Both of the products you wrote are soluble so this one is out.
3. A slightly ionized substance is formed. Both CuCl2 and Na2SO4 are strong electrolytes so this one is out.
4. Some oxidation/reduction reactions but this is not a redox reaction so this one is out.
okay how can you tell if they are strong electrolytes or the oxidation one
i understand the others
Strong electrolytes versus weak electrolytes. The question, really is how can you know a weak electrolyte. Look in a set of tables called ionization constants. There is a table for weak acids and another one for weak bases. If the material is listed there it is a weak electrolyte. If not it is a strong electrolyte. Most salts are strong electrolytes. Most organic compounds are weak electrolytes or non-electrolytes. On the subject of redox reactions, you haven't covered those yet, I don't expect, so don't worry about them until they arrive. The other three will get you through most reactions, even some of those that are redox reactions.
Ca(s) + Br2(l) --> CaBr2 is synthesis
my teacher also said that the cause of the reaction is stable electron configuration
is that the same thing as the electrolytes one
Answered above as a separate post.