How would u prepare each of the following solutions
100 mL of a 245 ppm solution of urea, CH4N2O, in water
and
How would u prepare each of the following solution
100 mL of an aqueous solution whose K+ concentration is 0.084 M
Write up the procedure, and I will gladly check it. I assume the ppm is on the basis of w/w
To prepare a 100 mL solution of a 245 ppm solution of urea in water:
1. Determine the mass of urea needed to obtain a concentration of 245 ppm (parts per million). The ppm concentration is defined as mass of solute (urea) per mass of solution (water + urea), multiplied by 10^6. Since the ppm is on a w/w (weight/weight) basis, the mass of urea needed can be calculated as follows:
Mass of urea = (245 ppm * 100 g solution) / 10^6 = 0.0245 g
2. Weigh out 0.0245 g of urea using a balance and transfer it to a clean and dry container.
3. Add approximately 100 mL of water to the container with urea. The exact volume may be adjusted to ensure accurate preparation of the 100 mL solution.
4. Stir the mixture well using a stirring rod until the urea is completely dissolved.
5. Transfer the solution to a 100 mL volumetric flask or any other suitable container.
6. Rinse the original container with a small amount of water and transfer the rinse water into the volumetric flask to ensure complete transfer of the solute.
7. Finally, add more water to bring the total volume to 100 mL. Mix well to ensure homogeneity.
To prepare a 100 mL solution with a K+ concentration of 0.084 M:
1. Determine the amount of potassium chloride (KCl) needed to obtain a concentration of 0.084 M. The molar concentration (M) is defined as the number of moles of solute (KCl) per liter of solution. Since we want a 100 mL solution, the moles of KCl can be calculated as follows:
Moles of KCl = Concentration (M) * Volume (L) = 0.084 M * 0.1 L = 0.0084 moles
2. Calculate the mass of KCl required using the molar mass of potassium chloride (74.5513 g/mol):
Mass of KCl = Moles of KCl * Molar Mass of KCl = 0.0084 moles * 74.5513 g/mol = 0.6295 g
3. Weigh out 0.6295 g of potassium chloride using a balance and transfer it to a clean and dry container.
4. Add approximately 100 mL of water to the container with KCl. The exact volume may be adjusted to ensure accurate preparation of the 100 mL solution.
5. Stir the mixture well using a stirring rod until the KCl is completely dissolved.
6. Transfer the solution to a 100 mL volumetric flask or any other suitable container.
7. Rinse the original container with a small amount of water and transfer the rinse water into the volumetric flask to ensure complete transfer of the solute.
8. Finally, add more water to bring the total volume to 100 mL. Mix well to ensure homogeneity.
To prepare a 100 mL solution of 245 ppm urea in water, you can follow the steps below:
1. Start by determining the mass of urea needed to achieve a concentration of 245 ppm (parts per million) in 100 mL of water. Since the ppm is on a weight-to-weight (w/w) basis, it means that for every 1 million parts of the solution, 245 parts should be urea.
Therefore, the mass of urea needed can be calculated using the following equation:
Mass of urea = (ppm / 1,000,000) * Mass of solution
Given that the mass of the solution is 100 mL (which is approximately equal to 100 grams, since the density of water is close to 1 g/mL), the mass of urea required would be:
Mass of urea = (245 / 1,000,000) * 100 g = 0.0245 g
2. Weigh out 0.0245 grams of urea using an analytical balance. Make sure the balance is calibrated and clean to ensure accurate measurements.
3. Transfer the weighed urea into a clean and dry 100 mL volumetric flask.
4. Add distilled water to the volumetric flask until the total volume reaches the 100 mL mark on the flask.
5. Cap the flask and mix the contents thoroughly to ensure the urea is fully dissolved in the water. You can gently swirl the flask or use a stir bar to aid in the dissolution process.
6. Your 100 mL solution of 245 ppm urea in water is now ready for use. Label the flask appropriately and store it in a suitable container to prevent contamination.
To prepare a 100 mL aqueous solution with a K+ concentration of 0.084 M, you can follow these steps:
1. Start by determining the amount of potassium (K+) needed to achieve a concentration of 0.084 M in 100 mL of water.
2. The molar mass of K+ is approximately 39.10 g/mol. Therefore, you can calculate the required mass of K+ using the formula:
Mass of K+ = Concentration (Molar) * Volume (L) * Molar Mass (g/mol)
Mass of K+ = 0.084 M * 0.1 L * 39.10 g/mol = 0.32724 g
The mass of K+ required is approximately 0.32724 grams.
3. Weigh out around 0.32724 grams of a compound containing potassium ions, such as potassium chloride (KCl), potassium nitrate (KNO3), or any other suitable potassium salt. Make sure the compound is anhydrous (free of water) to ensure accurate measurements.
4. Transfer the weighed potassium compound into a clean and dry 100 mL volumetric flask.
5. Add distilled water to the volumetric flask until the total volume reaches the 100 mL mark on the flask.
6. Cap the flask and mix the contents thoroughly to ensure the potassium compound is fully dissolved in the water. You can gently swirl the flask or use a stir bar to aid in the dissolution process.
7. Your 100 mL aqueous solution with a K+ concentration of 0.084 M is now ready for use. Label the flask appropriately and store it in a suitable container to prevent contamination.
Please note that it's important to handle chemicals and glassware with caution and follow appropriate safety measures. Also, specific quantities and procedures may slightly vary depending on your laboratory's protocols and the purity of the chemicals used.