Question

How many millileters of 6.0M NaOH must be used to prepare 1.0L of 0.10M NaOH? Show calculation with units.

Answer 1

Let for stock solution, Molarity M1 = 6.0 M and Volume V1 = ?

For the solution to be prepared, Molarity M2 = 0.10 M and Voume V2 = 1.0 L = 1000.0 mL

Now let us calculate milimoles of NaOH in each solutiin,

Milimoles = Molarity * Volume in mL

hence we write

Milimoles of NaOH n stock solution = M1 * V1 = 6.0 * V1 milimoles.

Milimoles of NaOH solution to be prepared = M2 * V2 = 0.10 * 1000 = 100.0 milimoles.

Now, by Law of dilution, Milimole number never change even on dilution.

M1*V1 = M2*V2

6.0 M * V1 = 0.1 M * 1000 mL

V1 = 100.0 / 6.0 mL

V1 = 16.7 mL (apprx.)

16.7 mL of 6.0 M NaOH need to taken.

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