Millimolarity Kcl B8C947

1. **State the problem:** Calculate the milliMolarity (mM) of a solution containing 0.7 g of KCl dissolved in 1 ml of solution. 2. **Formula and important rules:** MilliMolarity (mM) is the number of millimoles of solute per liter of solution. $$\text{mM} = \frac{\text{millimoles of solute}}{\text{volume of solution in liters}}$$ To find millimoles, use: $$\text{millimoles} = \frac{\text{mass of solute (g)}}{\text{molar mass (g/mol)}} \times 1000$$ 3. **Calculate molar mass of KCl:** Potassium (K) atomic mass = 39.1 g/mol Chlorine (Cl) atomic mass = 35.45 g/mol $$\text{Molar mass of KCl} = 39.1 + 35.45 = 74.55\ \text{g/mol}$$ 4. **Calculate millimoles of KCl:** $$\text{millimoles} = \frac{0.7}{74.55} \times 1000 = 9.39\ \text{mmol}$$ 5. **Convert volume to liters:** $$1\ \text{ml} = 0.001\ \text{L}$$ 6. **Calculate milliMolarity:** $$\text{mM} = \frac{9.39}{0.001} = 9390\ \text{mM}$$ **Final answer:** The milliMolarity of the solution is $$9390\ \text{mM}$$.