How would you prepare 250 mL of 0.150 M solution of CaCl2 from a 3.00 M stock solution? Specify the glassware that should be used.

Verified step by step guidance

1. insert step 1> Calculate the volume of the 3.00 M stock solution needed using the dilution formula: M1V1 = M2V2, where M1 is the molarity of the stock solution, V1 is the volume of the stock solution needed, M2 is the desired molarity, and V2 is the desired volume of the final solution.
2. insert step 2> Rearrange the dilution formula to solve for V1: V1 = (M2 * V2) / M1.
3. insert step 3> Substitute the given values into the equation: M1 = 3.00 M, M2 = 0.150 M, and V2 = 250 mL.
4. insert step 4> Calculate V1 to find the volume of the stock solution required.
5. insert step 5> Use a volumetric pipette to measure the calculated volume of the 3.00 M CaCl2 stock solution, transfer it to a 250 mL volumetric flask, and then add distilled water up to the mark on the flask to achieve the desired concentration.

Key Concepts

Molarity

Molarity (M) is a measure of concentration defined as the number of moles of solute per liter of solution. It is crucial for preparing solutions, as it allows chemists to calculate how much solute is needed to achieve a desired concentration. In this case, a 0.150 M solution of CaCl2 means there are 0.150 moles of CaCl2 in every liter of the solution.

Dilution

Dilution is the process of reducing the concentration of a solute in a solution, typically by adding more solvent. The dilution equation, C1V1 = C2V2, relates the concentrations and volumes of the stock solution (C1, V1) and the diluted solution (C2, V2). This concept is essential for determining how to prepare a specific molarity from a concentrated stock solution.

Glassware for Solution Preparation

The choice of glassware is important for accurately measuring and mixing solutions. A volumetric flask is ideal for preparing a specific volume of solution, as it provides precise measurements. A pipette or graduated cylinder can be used to measure the stock solution, ensuring that the correct volume is transferred for dilution.