Question

A solution contains 0.775 g Ca2 0.775 g Ca2 in enough water to make a 1925 mL1925 mL solution. What is the milliequivalents of Ca2 Ca2 per liter (mEq/L) for this solution

Answer 1

Answer: There will be 0.00002 meq per Liter of the solution.

Explanation:

Normality is defined as the umber of gram equivalents dissolved per liter of the solution.

$Normality=\frac{\text{no of gram equivalents} \times 1000}{\text{Volume in ml}}$

$Normality=\frac{\text{given mass}\times 1000}{\text {Equivalent mass}\times {\text{Volume in ml}}}$

Equivalent weight is calculated by dividing the molecular weight by n factor.   ${\text{Equivalent weight}}=\frac{\text{Molecular weight}}{n}$

n= charge for charged species  , For $Ca^{2+}$ , n =2

${\text{Equivalent weight}}=\frac{40}{2}=20g$

$\text{no of gram equivalents}=\frac{0.775g}{20g/mol}=0.04gramequivalents$

$Normality=\frac{0.04\times 1000}{1925}=0.02eq/L=0.00002meq/L$

Thus there will be 0.00002 meq per Liter of the solution.