What is 20 mEq equal to in milligrams?
The Correct Answer and Explanation is :
To convert milliequivalents (mEq) to milligrams (mg), you need to consider the specific ion or substance you are dealing with, as the conversion depends on the molecular weight and valence of that substance.
General Formula
The formula for converting mEq to mg is:
[
\text{mg} = \text{mEq} \times \frac{\text{molecular weight (mg/mmol)}}{\text{valence}}
]
Example Conversion: Sodium (Na⁺)
Let’s consider sodium (Na⁺) as an example. Sodium has a molecular weight of approximately 23 mg/mmol and a valence of +1.
Step 1: Apply the formula.
Using 20 mEq of sodium:
[
\text{mg} = 20 \, \text{mEq} \times \frac{23 \, \text{mg/mmol}}{1} = 460 \, \text{mg}
]
Thus, 20 mEq of sodium is equivalent to 460 mg.
Importance of Valence and Molecular Weight
The valence (the charge of the ion) is crucial in this calculation because it affects how many milliequivalents correspond to a given amount of substance. For example, if you were converting 20 mEq of calcium (Ca²⁺), which has a molecular weight of approximately 40 mg/mmol and a valence of +2, the calculation would look like this:
[
\text{mg} = 20 \, \text{mEq} \times \frac{40 \, \text{mg/mmol}}{2} = 400 \, \text{mg}
]
Summary
The conversion from mEq to mg is not straightforward without knowing the specific ion’s molecular weight and valence. Each substance will yield a different milligram equivalent depending on these factors. Therefore, always verify the ion you are dealing with for accurate conversions.