Dilution Problem - Find Initial Quantity

9. Altering Product Strength 9.1) Dilution 9.1.1) Dilution Find initial concentration in dilution Easy 1

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What quantity of a 38.25% solution do you need to make 84.5 mL of a 21.73% solution?. Round to the nearest tenth.

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lb equals 48 mL kg

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

    `Q_1` = initial quantity = `?\quadmL`.
    `C_1` = initial concentration = `38.25%`
    `Q_2` = final quantity = `84.5\quad mL`.
    `C_2` = final concentration = `21.73\quad %`

    Therefore, by rearranging the formula, we get:
    `Q_1 = (Q_2×C_2)/(C_1)` `therefore Q_1 = (84.5 × 21.73) /38.25=48\quadmL` in nearest tenth (Ans.).