Final answer:
To determine the amount of a stock solution to dilute, use the dilution equation M1V1 = M2V2, where M1 and V1 refer to the molarity and volume of the stock solution, while M2 and V2 refer to the desired diluted solution's molarity and final volume.
Step-by-step explanation:
When using a stock solution to prepare a less concentrated solution, the equation commonly used is known as the dilution equation, which is M1V1 = M2V2. Here, M1 represents the molarity of the stock solution, and V1 is the volume of the stock solution needed. M2 is the molarity of the diluted solution, and V2 is the final volume of the diluted solution. This equation calculates how much of the stock solution one must dilute to achieve a desired concentration in a new solution.
The process involves the following steps:
- Calculate the number of moles in the final solution by multiplying the desired volume (V2) by the desired molarity (M2).
- Divide the number of moles by the stock solution molarity (M1) to find the necessary volume of the stock solution (V1).
This method ensures that the amount of solute remains constant before and after dilution, only the volume of solvent changes. Remember that accuracy is important in these calculations, including proper unit conversion and significant figures.