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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: iloveebay4 on May 21, 2005, 08:15:07 PM

Title: Zinc Chloride and Potassium Sulphate
Post by: iloveebay4 on May 21, 2005, 08:15:07 PM

zinc chloride reacts with potassium sulfate.  How much zinc sulfate will be produced if 10.23g of zinc chloride react with 11.12g of potassium sulfate?


i got the products and everything..butt?  what do i do next ??? :'(!


thanks!

Title: Re:NEED HELP PLEASEPLEASEPLEASE (1 question)
Post by: jdurg on May 21, 2005, 09:57:38 PM

The very first step is writing out the balanced equation.  This way you will see the mole ratio of each component in the overall equation.  Next, you have to take a look at the masses of the reactants given to you.  Based upon the balanced equation you have written, which reactant is going to be completely consumed?  (I.E. what chemical will be all used up and what one will be in excess?)  Once you have that figured out, you can easily set up a ratio, using the balanced equation, to see how many moles of zinc sulfate you'll wind up with.  Once you've figured out the number of moles, finding out the mass is simple.  ;D

Title: Re:NEED HELP PLEASEPLEASEPLEASE (1 question)
Post by: AWK on May 22, 2005, 05:51:57 AM

All salts exists in solution as mixture of ions. The lowest solubility shows K2SO4. Hence you will not isolate desired ZnSO4 from solution.

Title: Re:NEED HELP PLEASEPLEASEPLEASE (1 question)
Post by: jdurg on May 22, 2005, 10:00:28 PM

Quote from: AWK on May 22, 2005, 05:51:57 AM

All salts exists in solution as mixture of ions. The lowest solubility shows K2SO4. Hence you will not isolate desired ZnSO4 from solution.

But that does not matter in this case.  The question is simply designed to help teach limiting factors in reactions.  Therefore, whether they are soluble or not does not matter one iota.  

Title: Re:NEED HELP PLEASEPLEASEPLEASE (1 question)
Post by: woelen on May 23, 2005, 04:38:22 AM

Quote from: jdurg on May 22, 2005, 10:00:28 PM

But that does not matter in this case.  The question is simply designed to help teach limiting factors in reactions.  Therefore, whether they are soluble or not does not matter one iota.  

If that is the case, then it is a bad question or the OP was not sufficiently clear with hist question. Initially, I could not do anything with this question, I simply did not understand it, because no reaction occurs if these two compounds are mixed. There are much better examples of (really occurring) reactions, where one of the reactants is the limiting compound in the total reaction result.

Title: Re:NEED HELP PLEASEPLEASEPLEASE (1 question)
Post by: Borek on May 23, 2005, 06:07:31 AM

Quote from: woelen on May 23, 2005, 04:38:22 AM

If that is the case, then it is a bad question or the OP was not sufficiently clear with hist question. Initially, I could not do anything with this question, I simply did not understand it, because no reaction occurs if these two compounds are mixed. There are much better examples of (really occurring) reactions, where one of the reactants is the limiting compound in the total reaction result.

I agree wholeheartedly with Wilco. There are enough examples of real reactions to be used in such cases to not justify using fake ones. This is a bad habit displayed by some stupid teachers - all it does is it adds confusion. Even without bad examples chemistry is full of overgeneralizations that make it hard to understand once you learn that what you have learnt before is only half-truth.