(type 3) Calculate mg per volume from mEq per volume

5. mEq and mOsmol 5.1) mEq 5.1.1) mEq - General

5.1.1.1) mEq from weight/volume Normal 1


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If monobasic sodium phosphate solution is mentioned as 0.0375 mEq/mL, then express the strength in percent w/v. Round your answer to the nearest hundredth. The molecular weight of monobasic sodium phosphate is 119.98 g/mol.


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lb equals 0.45 % kg

    The molecular weight of monobasic sodium phosphate = 119.98.
    Valence or charge = 1.
    Therefore, we can write: 119.98 mg = 1 mEq.
    Percent (w/v) is the number of grams of solute present per 100 mL of the solution.
    Since the question needs g/100 mL as the final unit, we keep 119.98 mg in the starting numerator. So, 1 mEq will be the denominator.
    Also, the solution contains 37.51 mEq per L; therefore, the mEq is used as the denominator for the second fraction, in order to cancel out. The dimensional analysis will be like this:

    `(0.0375 \quad mEq)/(1 \quad mL) × (119.98 \quad mg)/(1 \quad mEq) × (1 \quad g)/(1000 \quad mg) × (100 \quad mL)/(100 \quad mL) `

    ` = (0.45 \quad g)/(100 \quad mL)`.

    Therefore, it's 0.45% (w/v). Ans.