Question

Rx 1: How many mg/g of drug disodium citrate C6H6Na2O7  should be used in preparing 3L of a solution to supply 10 mEq of Na+ in each tablespoonful dose? MW of C6H6Na2O7 is 236

Answer 1

Volume of tablespoon = 15 ml

So concentration of the solution = 10 mEq/15 ml

In 15 ml ,10 mEq present.

In 3000 ml, 10/15 * 3000 = 2000 mEq

Molecular weight of C6H6Na2O7 = 236

From 1 mole of the compound,2 Eq of Na+ are liberated.

So 2000 mEq= 2 Eq liberated from 1 mole of the compound.

So weight of the drug to be used = 236 gram