What is the number of milliequivalents of potassium in 10 ml of 100 mg/ml potassium chloride solution?
(The molecular weight of potassium is 39 g and that of chlorine is 35 g)
When a compound is formed, the number of moles of each element that makes up the compound can be expressed in terms of an "equivalent." For example consider the compound NaCl. Here each mole of NaCl has 1 mole of Na and 1 mole of Cl which is 1/2 a mole of Cl2. We can say that 1 equivalent of Na and half an equivalent of Cl2 are required in 58 g of NaCl. A milliequivalent or meq is 1/1000 of an equivalent.
As a general rule, for monovalent ions, 1 meq = 1 mmol, for divalent ions, 1 meq = 0.5 mmol and for trivalent ions, 1 meq is approximately equal to 0.333 mmol.
We need to find the milliequivalents of potassium in 10 ml of 100 mg/ml potassium chloride solution. 10 ml of 100 mg/ml solution has 1000 mg of KCl. This is equal to 1000/74 = 13.51 mmol. The number of milliequivalents of potassium in 10 ml of 100 mg/ml potassium chloride solution is 13.5
The correct answer is option b or 13.5