how would you prepare 300 ml of a 10% CaCl2 solution (w/w)?
To prepare a 10% CaCl2 solution (w/w) with a volume of 300 ml, you need to follow these steps:
Step 1: Determine the mass of CaCl2 needed.
- The concentration is given as a weight percentage (w/w), which means that the percentage refers to the weight of the solute (CaCl2) in the total weight of the solution.
- A 10% CaCl2 solution means that 10 grams of CaCl2 is present in 100 grams of the solution.
- To calculate the mass of CaCl2 needed for 300 ml of solution, you can use the equation:
Mass of CaCl2 = (Volume of solution (ml) * Concentration (g/100g)) / 100
Plugging in the values, we have:
Mass of CaCl2 = (300 ml * 10 g/100 g) / 100
Mass of CaCl2 = (300 * 10) / 100
Mass of CaCl2 = 30 grams
Step 2: Measure out 30 grams of CaCl2.
- Use a balance or a weighing scale to measure the required amount of CaCl2 accurately.
Step 3: Dissolve CaCl2 in a solvent to make 300 ml of solution.
- Pour the measured 30 grams of CaCl2 into a container.
- Add a suitable solvent, such as water, to the container.
- Stir or shake the container until the CaCl2 is completely dissolved and the solution is uniform.
Step 4: Adjust the final volume to 300 ml.
- Measure the total volume of the solution using a graduated cylinder or a volumetric flask.
- If the volume is less than 300 ml, add more solvent (e.g., water) to reach the desired volume.
- If the volume exceeds 300 ml, remove some of the excess solution until you reach the desired volume.
Once you have completed these steps, you will have successfully prepared 300 ml of a 10% CaCl2 solution (w/w).