Dilution Problem - Find Initial Concentration

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

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What concentration of a 28.5 mL solution do you need to make 240 mL of a 2.43% solution?

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lb equals 20.5 % 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 = `28.5\quadmL`.
    `C_1` = initial concentration = `?\quad%`
    `Q_2` = final quantity = `240\quad mL`.
    `C_2` = final concentration = `2.43\quad %`

    Therefore, rearranging the formula, we get:
    `C_1 = (Q_2 × C_2)/(Q_1)`

    `therefore C_1 = (240 × 2.43) /28.5=20.5\quad%` (Ans.).

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