Which of the following actions would most likely be performed when designing a chemical solution in the laboratory?

• A. Determining the atomic number of the solvent
• B. Observing the color change of a precipitate
• C. Measuring the melting point of the solute
• D. Calculating the amount of solute needed to achieve a desired concentration

Answer: (D)

Verified step by step guidance

1. Understand the goal of designing a chemical solution, which typically involves preparing a solution with a specific concentration.
2. Recall that concentration is defined as the amount of solute dissolved in a given volume of solvent, commonly expressed in molarity (moles per liter).
3. Identify that to prepare a solution of desired concentration, you need to calculate the amount of solute required using the formula: \(C = \frac{n}{V}\), where \(C\) is concentration, \(n\) is moles of solute, and \(V\) is volume of solution.
4. Rearrange the formula to find the moles of solute needed: \(n = C \times V\).
5. Convert moles of solute to mass if necessary by using the molar mass: \(\text{mass} = n \times \text{molar mass}\), so you can accurately weigh the solute to prepare the solution.