You are given a 25.0mL volumetric flask, describe the procedure you will follow in lab to prepare 25.0mL of a 0.019 M solution of NaCl?
To prepare a 25.0 mL of a 0.019 M solution of NaCl using a 25.0 mL volumetric flask, follow these steps:
1. Start by gathering the necessary materials and equipment: a 25.0 mL volumetric flask, a balance, a source of deionized water, and a source of NaCl.
2. Use the balance to measure out the appropriate amount of NaCl. Since the desired concentration is 0.019 M, you need to calculate the mass of NaCl required using its molar mass.
3. The molar mass of NaCl is 58.44 g/mol. To find the mass of NaCl required, use the formula:
Mass (g) = Molarity (mol/L) * Volume (L) * Molar mass (g/mol)
In this case, plug in the values: 0.019 mol/L for the molarity and 0.025 L (since the volumetric flask has a capacity of 25.0 mL) for the volume.
Mass (g) = 0.019 mol/L * 0.025 L * 58.44 g/mol
4. Calculate the mass, which should be approximately 0.02796 g (rounded to five decimal places).
5. Carefully weigh out the calculated mass of NaCl using a balance, ensuring accuracy.
6. Once the correct mass of NaCl is measured, transfer it into the empty 25.0 mL volumetric flask using a funnel or other suitable means.
7. Fill the volumetric flask with deionized water slowly until it reaches the calibration mark, which is the line on the neck of the flask. Use a dropper or a pipette if needed to avoid overfilling.
8. Once filled, seal the flask with the stopper and invert it several times to ensure thorough mixing and dissolution of the NaCl in the deionized water.
9. Take note that the solution in the volumetric flask now has a volume of 25.0 mL and a concentration of 0.019 M. It is ready to be used for laboratory experiments or analysis.
Remember to always follow proper safety procedures and wear appropriate protective equipment when handling chemicals in the lab.