1. Understand the Units:
* mM (millimolar): This is a unit of concentration, representing millimoles (mmol) of solute per liter (L) of solution.
* NaCl (sodium chloride): This is the chemical formula for table salt.
2. Calculate the Mass of NaCl Needed:
* Molar Mass of NaCl: 58.44 g/mol
* Conversion: 1 mole = 1000 mmol
* Calculation:
* (300 mmol NaCl / L) * (1 L) * (1 mol NaCl / 1000 mmol) * (58.44 g NaCl / 1 mol NaCl) = 17.53 g NaCl
3. Prepare the Solution:
* Step 1: Weigh out 17.53 grams of NaCl using a balance.
* Step 2: Add the NaCl to a 1-liter volumetric flask.
* Step 3: Add a small amount of distilled water to the flask and swirl gently to dissolve the NaCl.
* Step 4: Carefully add more distilled water to the flask until the solution reaches the 1-liter mark on the flask.
* Step 5: Stopper the flask and invert it several times to ensure the solution is thoroughly mixed.
Important Notes:
* Distilled Water: Always use distilled water to ensure accurate concentrations.
* Volumetric Flask: A volumetric flask is essential for accurate volume measurements.
* Solubility: NaCl is highly soluble in water. If you're having trouble dissolving the NaCl, gently heat the solution with a hot plate (never on a burner) until it dissolves.
Safety:
* Wear appropriate safety goggles and gloves while handling chemicals.
* Work in a well-ventilated area.
Let me know if you'd like to calculate the mass of NaCl needed for a different concentration or volume of solution!
