Question

1. The molecular weight of MgCl₂ is 95. How many milligrams is 1mEq per liter?
2. The molecular weight of NaH₂PO₄.H₂O is 138. How many milligrams is 1mEq per liter?

Answer 1

Answer: 1 mEq means ( 1 milli equivalent) means 1/1000 times the equivalent mass of given compound.

Molar mass of MgCl₂ = 95 g/mol (given)

Since Mg is di-positive cation (Mg⁺²) so the equivalent mass of MgCl₂ = 95/2 g = 47.5 g/equivalent

1 mEq of MgCl₂ = (1/1000) x 47.5 g = 47.5 x 10^-3 g = 47.5 mg

Molar mass of NaH₂PO₄.H₂O = 138 g/mol (given)

Since Na is mono-positive cation (Na⁺) so the equivalent mass of NaH₂PO₄.H₂O = 138/1 g = 138 g/equivalent

1 mEq of NaH₂PO₄.H₂O = (1/1000) x 138 g = 138 x 10^-3 g = 138 mg