n the spectroscopic analysis of many substances, a series of standard solutions of known concentration are measured to generate a calibration curve. How would you prepare standard solutions containing 10.0, 25.0, 50.0, 75.0, and 100. ppm of copper from a commercially produced 1000.0 ppm solution? Assume each solution has a final volume of 100.0 mL. (ppm = mg solute/kg solution)

Question

n the spectroscopic analysis of many substances, a series of standard solutions of known concentration are measured to generate a calibration curve. How would you prepare standard solutions containing 10.0, 25.0, 50.0, 75.0, and 100. ppm of copper from a commercially produced 1000.0 ppm solution? Assume each solution has a final volume of 100.0 mL. (ppm = mg solute/kg solution)

100. ppm
75.0 ppm
50.0 ppm
25.0 ppm
10.0 ppm

Answer 1

To prepare standard solutions of known concentration containing 10.0, 25.0, 50.0, 75.0, and 100.0 ppm of copper from a commercially produced 1000.0 ppm solution, you can use the method of dilution.

Here are the steps to prepare each standard solution:

1. Calculate the volume of the 1000.0 ppm solution required to achieve the desired concentration in the final solution.

To do this, you can use the equation:
C1V1 = C2V2

Where:
C1 = initial concentration (1000.0 ppm)
V1 = initial volume (unknown)
C2 = desired concentration (10.0, 25.0, 50.0, 75.0, or 100.0 ppm)
V2 = final volume (100.0 mL)

Rearranging the equation to solve for V1:
V1 = (C2 x V2) / C1

2. Calculate the volume of the 1000.0 ppm solution that needs to be added to achieve the desired concentration.

Subtract the calculated volume (V1) from the final volume (V2) to determine the volume of the solvent (usually water) that needs to be added.

Solvent volume = V2 - V1

3. Prepare each standard solution according to the calculated volumes.

For example, let's calculate the preparation of the 10.0 ppm solution:

V1 = (10.0 ppm x 100.0 mL) / 1000.0 ppm
= 1.0 mL

Solvent volume = 100.0 mL - 1.0 mL
= 99.0 mL

So, to prepare the 10.0 ppm copper solution, take 1.0 mL of the 1000.0 ppm copper solution and add 99.0 mL of the solvent (usually water) to reach a final volume of 100.0 mL.

Repeat this process for the other desired concentrations (25.0, 50.0, 75.0, and 100.0 ppm) using their respective calculations.

Note: Ensure that all measurements are accurate and precise when preparing standard solutions for spectroscopic analysis, as any errors can affect the accuracy and reliability of the calibration curve.