### Dilution Problem - Find Initial Quantity

9. Altering Product Strength 9.1) Dilution 9.1.1) Dilution

9.1.1.1) Find initial concentration in dilution Easy 1

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What quantity of a 39% solution do you need to make 270 mL of a 2.67% solution?. Round to the nearest tenth.

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lb equals 18.5 mL kg

This is a volume expansion or concentration dilution type problem. The essential formula is Q_1C_1 = Q_2C_2.
Here,

Q_1 = initial quantity = ?\quadmL.
C_1 = initial concentration = 39%
Q_2 = final quantity = 270\quad mL.
C_2 = final concentration = 2.67\quad %

Therefore, by rearranging the formula, we get:
Q_1 = (Q_2×C_2)/(C_1) therefore Q_1 = (270 × 2.67) /39=18.5\quadmL in nearest tenth (Ans.).

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