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What would be the concentration of a solution made by diluting 45.0 mL of 4.2 M KOH to 250 mL?

Answer 1

Henry Antrim

As always, #"concentration"="Moles of solute"/"Volume of solution"..........#

Here (i), we determine the number of "moles of solute" in the starting volume:

#=45xx10^-3Lxx4.2*mol*L^-1=0.189*mol# with respect to #KOH(aq)#.

After that, (ii) we divide this amount by the volume of solution that is NEW:

#"Concentration"=(0.189*mol)/(0.250*L)~=0.8*mol*L^-1# with respect to #KOH#.

Since the volume has roughly increased five times, the concentration has roughly decreased five times as well.

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Answer 2

Cooper Adams

The concentration of the solution after diluting 45.0 mL of 4.2 M KOH to 250 mL would be approximately 0.756 M.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.