What is the concentration of...

[seremay]

I really need help with this, a hint was given about the dilution equation
(M₁V₁ = M₂V₂)

What is the concentration of Fe₃+ in a solution made by combining 2.40 mL of 0.005000 M Fe(NH₄)(SO₄)₂·12H₂O, 2.00 mL of 0.100 M KSCN, 1.00 mL of HNO₃ and 14.60 mL of water.

[GrahamKemp]

I really need help with this, a hint was given about the dilution equation
(M₁V₁ = M₂V₂)

What is the concentration of Fe₃+ in a solution made by combining 2.40 mL of 0.005000 M Fe(NH₄)(SO₄)₂·12H₂O, 2.00 mL of 0.100 M KSCN, 1.00 mL of HNO₃ and 14.60 mL of water.

IIf no reaction takes place then it would be simply:

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M2 = M1 V1 / V2

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 = ( 0.00500 M ) ( 2.40 mL ) / ( 2.40 + 2.00 + 1.00 + 14.60 mL )

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 = 0.000600 M of Fe{3+}

However.

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Fe{3+} + 3 SCN{-} = Fe(SCN)3 (s)

, so every three moles of KSCN will remove 1 mole of

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Fe{3+}

from solution.

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M4 = M3 V3 / V4

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 = ( 0.100 M ) ( 2.00 mL ) / ( 2.40 + 2.00 + 1.00 + 14.60 mL )

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 = 0.0100 M of SCN{-}

Which is vastly in excess of the

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Fe{3+}

so basically the answer is

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0.00000 M Fe{3+}