describe how you would prepare 250.0 mL of a .500 M solution of NaCl by using apparatus found in a chemistry lab.
To prepare a 250.0 mL of a 0.500 M solution of NaCl using apparatus found in a chemistry lab, you will need the following materials:
1. NaCl (sodium chloride): Ensure you have enough NaCl to prepare the desired volume and concentration of the solution.
2. Analytical balance: Use this to carefully weigh the required amount of NaCl.
3. Beakers: Select a suitable-sized beaker to hold the solution.
4. Graduated cylinder: Use this to measure the required volume of water.
5. Stirring rod: For mixing the solution.
6. Weighing boat or weighing paper: It helps in accurately measuring the mass of NaCl.
7. Volumetric flask: A flask used to prepare precise volumes of solutions.
Here are the steps involved in preparing the solution:
1. Calculate the mass of NaCl needed using the formula:
Mass = Moles × Molecular weight.
In this case, the molecular weight of NaCl is 58.44 g/mol.
To prepare a 0.500 M NaCl solution, you need to calculate the moles of NaCl required using the equation:
Moles = Molarity × Volume (in liters).
Here, the volume is 0.250 L (250.0 mL = 0.250 L) and the molarity is 0.500 M.
So, Moles = 0.500 × 0.250 = 0.125 moles.
2. Measure the calculated mass of NaCl using an analytical balance and transfer it into a weighing boat or weighing paper.
3. Pour the measured NaCl into a beaker containing a small amount of deionized water. Dissolve the NaCl in the water by stirring the mixture with a stirring rod until it is completely dissolved.
4. Transfer this NaCl solution into a 250.0 mL volumetric flask using a funnel, ensuring you wash out any remaining residue in the beaker.
5. Add deionized water into the volumetric flask until the solution reaches the calibration mark (should be 250.0 mL). Using a graduated cylinder is an effective way to measure the exact volume of water needed.
6. Mix the solution thoroughly by inverting the flask several times or using a stirring rod.
Now, you have successfully prepared 250.0 mL of a 0.500 M NaCl solution using the apparatus found in a chemistry lab.
To prepare a 250.0 mL of a 0.500 M solution of NaCl in a chemistry lab, you will need the following apparatus:
1. Balance: To measure the mass of NaCl.
2. Volumetric flask: A 250.0 mL volumetric flask to prepare and measure the final volume accurately.
3. Weighing boat or container: To hold and weigh the desired amount of NaCl.
4. Analytical balance: Highly accurate balance to measure the mass of NaCl.
5. Deionized water:used to dissolve the NaCl and make up the final volume.
6. Stirring rod: To mix the solution evenly.
Here are the steps to prepare the solution:
1. Weighing NaCl: Using the analytical balance, measure out the appropriate amount of NaCl needed to make a 0.500 M solution.
The formula to calculate the mass of NaCl can be defined as:
Mass of NaCl (g) = volume of solution (L) × molarity of solution (mol/L) × molar mass of NaCl (g/mol)
The molar mass of NaCl is approximately 58.5 g/mol.
2. Dissolving NaCl: Transfer the weighed NaCl into the weighing boat or container, and carefully transfer it to the 250 mL volumetric flask.
3. Adding water: Fill the volumetric flask approximately halfway with deionized water.
4. Dissolving NaCl: Swirl the flask gently to dissolve the NaCl in the water. Be sure to dissolve all the solid completely.
5. Adjusting the volume: Once the NaCl is dissolved, add more deionized water to the volumetric flask until the solution reaches the calibration mark on the neck of the flask.
It is crucial not to pour directly into the flask; use a dropper or funnel to add water to the flask gradually.
6. Mixing the solution: After adjusting the volume, insert a stirring rod into the flask and gently mix the solution to ensure it is uniform.
7. Storing the solution: Once the solution is well-mixed, label the flask with the necessary information such as the date, concentration, and chemical name. Store the solution securely in a suitable container.
By following these steps, you will successfully prepare 250.0 mL of a 0.500 M NaCl solution using the apparatus found in a chemistry lab.
mols NaCl needed = M x L = 0.500 x 0.250 = about 0.125
grams NaCl = mols needed x molar mass = aboaut 0.125 x 58 (you need to use a better number than this estimate) = about 7.3 g.
Therefore, place 7.3 g NaCl in a 500 mL volumetric flask, add some water, swirl until all of the NaCl is dissolved, then add distilled water to the mark.