A solution contains the ions Ag+, Pb2+, and Ni2+. Dilute solutions of NaCl, Na2SO4, and Na2S are available to separate the positive ions from each other. In order to effect separation, the solutions should be added in which order?

Here’s what I got.

The idea here is that you need to make sure that each added solution only preicipates one of the cations.

That is, if you add the first solution and more than one cation precipitates, you will loose track of the exact numbers of cations of each type you had in the original solution.

The trick here is to find the solution that only precipitates one cation and the solution that precipitates all three cations and add them first and last, respectively.

Take a look at a table of the solubility rules for

Your three dilute are

  • sodium chloride, ##”NaCl”##
  • sodium sulfate, ##”Na”_2″SO”_4##
  • sodium sulfide, ##”Na”_2″S”##

This means that you must look for which pair of cation – anion will produce the desired precipitation sequence.

Notice that chlorides, which are that contain the chloride anion, ##”Cl”^(-)##, are mostly soluble with the exception of those that contain the ##”Ag”^(+)## and ##”Pb”^(2+)## cations.

This means that you cannot add the sodium chloride first, since that would precipitate two cations.

The same is true for sulfates, which are that contain the sulfate anion, ##”SO”_4^(2-)##. Once again, the ##”Ag”^(+)## and ##”Pb”^(2+)## cations would be precipitated if you were to add the sodium sulfate solution first.

On the other hand, the sodium sulfide solution would precipitate all three cations, so you’ve found the solution to add last.

So the strategy to find the solution that only precipitates one cation is no longer standing.

Now, how would you determine which solutions should come first?

You take a look at the solubilities of silver chloride, ##”AgCl”##, and of lead(II) chloride, ##”PbCl”_2##.

The important thing to notice here is that silver chloride remains insoluble at higher temperatures, but that the solubility of lead(II) chloride actually increases as temperature increases.

This means that if you use the sodium chloride to precipitate both ions at room temperature, then heat the solution, you can dissolve the lead(II) chloride and free up the ##”Pb”^(2+)## cations again.

You’d then go on to add the sodium sulfate solution and precipitate the ##”Pb”^(2+)## cations, and the sodium sulfide solution to precipitate the ##”Ni”^(2+)## cations.

So, the order in which I’d add these solutions is

  • sodium chloride, ##”NaCl”##
  • sodium sulfate, ##”Na”_2″SO”_4##
  • sodium sulfide, ##”Na”_2″S”##

SIDE NOTE I think that you can use the same technique if you add the sodium sulfate solution first.

Lead(II) sulfate is much less soluble in aqueous solution than silver sulfate as temperature increases, so basically you could

  • precipitate both the lead(II) and silver cations by using sodium sulfate
  • heat up the solution to dissolve the silver sulfate and free up the silver cations
  • add the sodium chloride to precipitate the silver cations

I would still go for the first sequesnce of solutions, though.

Calculate Your Essay Price
(550 words)

Approximate price: $22

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
The price is based on these factors:
Academic level
Number of pages
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more

Order your essay today and save 10% with the coupon code: best10