hey guys im stumped and burning out. Its mid term time. I got 5 midterms and lab test.
i think im making this more complex than needed
what is 10mg/dL Ca in mEq/L
can u show me a simple way using the valence ? My answer doesnt make sense.
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N=(gram solute/mw)/L
(20mg/40.078)dL--->
=0.499 /dL
converts to 5.0 mEq/L
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is there a simpler way by using the normality and valence ?
I don't know that it's any simpler. You have used essentially the same thing. I usually do it in steps.
N = number milliequivalents/mL = me/mL and
me = molecular weight/valence
40/2 = 20 = eq wt or 0.02 for meq wt.
10 mg/dl = 0.01 g/0.1L = 0.1 g/L
0.1g/20 = 0.005 eq/L = 5 me/L.
thanks dr bob
Yes, there is a simpler way to convert 10mg/dL of Ca to mEq/L by using the normality and valence. Here's how:
1. First, determine the molar mass of calcium (Ca). The molar mass of Ca is 40.078 g/mol.
2. Next, convert the concentration from mg/dL to g/L. Since 1 mg = 0.001 g and 1 dL = 0.1 L, the conversion factor is 0.001 g/0.1 L = 0.01 g/L.
3. Now, calculate the number of moles of calcium by dividing the concentration (in g/L) by the molar mass of calcium. In this case, it would be 0.01 g/L / 40.078 g/mol = 0.000249 mol/L.
4. The normality (N) of a solution is defined as the number of equivalents per liter (eq/L). Since calcium has a valence of 2, each mole of Ca corresponds to 2 equivalents. Therefore, the number of equivalents of calcium per liter is 0.000249 mol/L * 2 eq/mol = 0.0004985 eq/L.
5. Finally, since 1 milliequivalent (mEq) is equal to 0.001 equivalents (eq), you can convert the number of equivalents to milliequivalents by multiplying by 1000. Thus, 0.0004985 eq/L * 1000 = 0.4985 mEq/L.
So, the concentration of 10mg/dL Ca is approximately 0.4985 mEq/L when using the normality and valence method.