What is a recommended storage method for ammonia to prevent degradation?

What is a recommended storage method for ammonia to prevent degradation?

• A. Refrigeration at 4°C
• B. Slurry of crushed ice and water
• C. Frozen at -20°C
• D. Room temperature

Answer: (B)

Maintaining a cold environment is key to preserving ammonia and preventing its degradation. An ice-water slurry keeps the sample at around 0°C, which rapidly cools the contents and maintains a temperature that slows both volatilization of ammonia and any microbial or chemical processes that could alter its form. This near-freezing, liquid-cold state minimizes losses and changes in concentration more effectively than simply using a 4°C fridge, which doesn’t provide as rapid or uniform cooling. Freezing at -20°C can cause physical changes and complications when thawed, and storing at room temperature would allow degradation to proceed quickly. So, the crushed ice and water mixture offers the right balance: quick, uniform cooling to near 0°C without freezing, helping preserve ammonia.

Maintaining a cold environment is key to preserving ammonia and preventing its degradation. An ice-water slurry keeps the sample at around 0°C, which rapidly cools the contents and maintains a temperature that slows both volatilization of ammonia and any microbial or chemical processes that could alter its form. This near-freezing, liquid-cold state minimizes losses and changes in concentration more effectively than simply using a 4°C fridge, which doesn’t provide as rapid or uniform cooling. Freezing at -20°C can cause physical changes and complications when thawed, and storing at room temperature would allow degradation to proceed quickly. So, the crushed ice and water mixture offers the right balance: quick, uniform cooling to near 0°C without freezing, helping preserve ammonia.