A chemistry lab experiment involves mixing two solutions. Solution A contains 20% salt and Solution B contains 40% salt. If 150 mL of Solution A is mixed with 250 mL of Solution B, what is the concentration of salt in the resulting mixture? - Parker Core Knowledge

Understanding the Context

The Science Behind Mixing Concentrations

When solutions combine, the amount of solute remains the same, but the total volume increases. Salt concentration drops because the same total amount of salt now distributes across a larger volume. The final concentration depends on both the ratio of volumes and their individual concentrations.

Mathematically, total salt is calculated from each solution:
Salt from Solution A = 20% of 150 mL = 0.20 × 150 = 30 mL salt
Salt from Solution B = 40% of 250 mL = 0.40 × 250 = 100 mL salt
Total salt = 30 + 100 = 130 mL salt

Key Insights

Total volume after mixing = 150 + 250 = 400 mL

The resulting concentration is then:
Concentration = (Total salt / Total volume) × 100 = (130 / 400) × 100 = 32.5% salt

Is This Mix Effective? Practical Insight

This experiment demonstrates a common scenario in real science: dilution and concentration mixing. Though straightforward, it illustrates core principles used in fields like pharmaceuticals, food science, and environmental testing. Recognizing how concentrations change helps users make informed choices—whether adjusting saline solutions for medicinal use, fine-tuning high-salt recipes, or analyzing natural water sources.

Final Thoughts

While always vital to follow safety guidelines—especially with saline compounds or scientific equipment—the basic experiment remains accessible and reliable, making it a popular topic in educational content.

Common Questions About Mixing Salt Solutions

**Q: Does mixing 150 mL of 20% salt with 250 mL of 40% salt produce a neutral or