You are a lab technician and must create 250 ml of a 17% salt solution. You have available three stock solutions. You have a one liter container of a 5% salt, a 500 ml container of a 28% salt solution, and a 400 ml container of a 40% salt solution.
Discuss and explain the sources of error that may be occurring in creating the mixtures
How are you to create the 17% soln? From any of the already made + water or is it to be some combination of the three given?
When creating mixtures, it is important to understand the sources of error that can occur. In this case, the lab technician needs to create 250 ml of a 17% salt solution using the available stock solutions. Several sources of error might arise during this process:
1. Measurement errors: Accurate measurement of the volumes is crucial in creating the desired solution. Errors can occur due to imprecise measuring tools, improper technique, or incorrect reading of the measurement scale.
2. Mixing errors: Proper mixing is necessary to ensure homogeneity of the solution. Insufficient or improper mixing can lead to uneven distribution of the salt, resulting in an inaccurate concentration.
3. Contamination: If any form of contamination occurs during the preparation process, it can impact the accuracy of the resulting solution. Contamination can happen from foreign substances, improperly cleaned equipment, or cross-contamination from previous experiments.
4. Incorrect concentration of stock solutions: If the concentration of the stock solutions is different from what is stated on the container label, it can lead to deviations in the desired final concentration. It is important to confirm the accuracy of the concentration of the stock solutions before utilizing them.
5. Evaporation: When working with open containers, evaporation may occur. Evaporation can lead to concentration changes in the solutions, resulting in inaccurate final concentrations.
To minimize these errors, the lab technician should follow good laboratory practices. Use calibrated measuring equipment, ensure thorough mixing, clean equipment properly, verify the accuracy of stock solution concentrations, and minimize exposure to open air to prevent evaporation. Additionally, conducting multiple trials or averaging multiple measurements can help account for any minor variations and improve accuracy.