Thus, the technician needs 3 liters of the 50% saline solution. - Redraw

Understanding the Context

A 50% saline solution contains 500 grams of sodium chloride (NaCl) dissolved in 1 liter of water, resulting in a dense, pale yellow solution. Chemically, it’s an isotonic solution (approximately 0.9% NaCl by weight), commonly used in medical injections, calibration of equipment, and as a reagent in labs.

Why does a technician require 3 liters? Applications such as:

• Calibrating saline infusion pumps
  
• Preparing standardized solutions in research
  
• Conducting electrolyte balance experiments

...demand controlled, measurable volumes. Obtaining exactly 3 liters ensures reproducibility and consistency in tests.

Key Insights

Preparing 3 Liters of 50% Saline Solution

To obtain 3 liters of 50% saline, technicians typically dissolve sodium chloride in distilled water. The reaction is:

NaCl (s) → Na⁺ (aq) + Cl⁻ (aq)
Mass ratio: ~29.4 g NaCl in 1 L water = 50% by weight

To prepare 3 liters:

• Dissolve 88.2 grams of NaCl (~50g NaCl + 1 liter of water) in a volumetric flask
  
• Stir thoroughly to ensure full dissolution and uniform concentration
  
• Verify with a calibrated balance and pH/mass meter

This method ensures accurate 0.9% NaCl solution at optimal density and stability.

Final Thoughts

Applications Requiring Consistent Volume

1. Medical Training Labs:
   Technicians use 3 L batches to supply saline for intravenous drip calibration, drug solutions, and diagnostic device testing.

2. Research Facilities:
   Scientists preparing regression models on osmotic effects need precise saline volumes. 3 liters offers sufficient batches without frequent re-preparation.

3. Industrial Quality Control:
   Manufacturers of medical devices rely on accurate saline inputs for rinse cycles, cleaning validation, and performance checks.

Safety & Storage Considerations

• Store in corrosion-resistant containers labeled for saline and concentrated solutions.
  
• Handle gloves and eye protection; saline concentrate can irritate mucous membranes.
  
• Keep sealed to prevent absorption of moisture, which affects concentration.