Question

I've been stuck on this for so long...

A solution of 116 mL of 0.160 M KOH is mixed with a solution of 220 mL of 0.250 M NiSO4.
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What is the concentration of Ni2+ that remains in solution?
What is the concentration of SO2−4 that remains in solution?
What is the concentration of K+ that remains in solution?

Answer 1

@DubSubNation
You need to find out if all the ions remain in solution. If there is a combination of ions that has a low solubitlity, then they \(may\) combine to form a precipitate.
We know that all K+ salts are soluble, so no worries there.
Ni(OH)2 has a solubility of 0.16g/L (Look up the Chemical Rubber Handbook or just Google), so it is a suspect for precipitate.
Now write down the chemical equation assuming precipitation occurs, and determine the limiting reagent.
Using the amount of the limiting reagent, calculate the amount of product (Ni(OH)2) formed and determine if precipitation will occur.
If so, calculate the accurate amount of solids formed based on the ions concentration present, and [SO4--], [K+], [Ni++], ...

Answer 2

this isn't a dilution problem, this is a stoichiometry problem, as @mathmate has said

Answer 3

...I still don't understand what you guys are talking about. Is there no math involved?

"calculate the accurate amount of solids formed based on the ions concentration present, and [SO4--], [K+], [Ni++], ..." what does this mean? I already have the precipitates and all that, but do I do something with it? I'm in college, and I'm literally having to teach myself how to do this stuff.

Answer 4

@mathmate @JFraser

Answer 5

you're given the amounts of 2 reactants from a chemical equation.

you need to put together the reaction that's occurring, and use stoichiometry and the mole ratio to find the amounts of each product formed, and the amounts of the reactants that may be left over

Answer 6

Your reaction has to look something like this:\[NiSO_4 + KOH \rightarrow K_2SO_4 + Ni(OH)_2\] ...but it's not balanced yet