how would you prepare 300 ml of a 10% CaCl2 solution (w/w)?
What's the density of 10%CaCl2?
You would want 30 g CaCl2/300 g soln but that isn't 300 mL. That would be 300 g CaCl2 in 270 g H2O and that will produce a volume that is probably about 280 mL.
To prepare a 10% CaCl2 solution (w/w) with a volume of 300 ml, here's how you can calculate and carry out the preparation:
Step 1: Understand the term "w/w"
The term "w/w" stands for "weight/weight" and represents the ratio of the weight of the solute (CaCl2) to the weight of the solution (CaCl2 + solvent).
Step 2: Determine the weight of CaCl2 needed
To calculate the weight of CaCl2 needed, you'll use the formula:
Weight of CaCl2 = Percentage concentration / 100 * Weight of solution
We know the desired percentage concentration is 10%, and the desired weight of the solution is 300 ml (which is equivalent to 300 grams since 1 ml of water weighs approximately 1 gram).
Weight of CaCl2 = 10 / 100 * 300g = 30g
Therefore, you would need 30 grams of CaCl2.
Step 3: Prepare the 10% CaCl2 solution
To prepare the solution, follow these steps:
1. Weigh 30 grams of CaCl2 using a balance.
2. Add the CaCl2 to a beaker or container.
3. Add enough water to make the total volume 300 ml.
4. Stir the solution thoroughly until the CaCl2 is completely dissolved.
5. Use a measuring cylinder or graduated cylinder to ensure the final volume is precisely 300 ml.
That's it! You have now prepared a 300 ml solution of 10% CaCl2 (w/w).