ANS:B - vaporises at normal temperature.

Though liquid ammonia itself is a fertilizer with a high nitrogen content (about 82%), it is commonly not used as such in tropical countries like India due to its toxicity and highly corrosive nature. Liquid ammonia can be hazardous to handle and transport, and it poses risks to both human health and the environment. Here's why liquid ammonia is not commonly used as a fertilizer in tropical countries like India:

1. Toxicity: Liquid ammonia releases ammonia gas (NH3) when it comes into contact with air or water. Ammonia gas is highly toxic and can cause irritation, burns, and respiratory problems if inhaled. It can also cause chemical burns if it comes into contact with the skin or eyes.
2. Corrosiveness: Ammonia is highly corrosive to metals and other materials. It can cause damage to equipment, storage tanks, and infrastructure if not handled properly. The corrosive nature of liquid ammonia presents challenges for storage, handling, and application in agricultural settings.
3. Safety Concerns: Handling and transporting liquid ammonia require strict safety measures and specialized equipment to prevent leaks, spills, and accidents. The risks associated with handling liquid ammonia make it less practical for use as a fertilizer in agricultural operations, especially in densely populated areas.
4. Availability and Cost: Liquid ammonia is produced primarily for industrial purposes, such as fertilizer manufacturing, refrigeration, and chemical synthesis. While it is available in sufficient quantities for industrial applications, its use as a direct fertilizer is limited due to safety considerations and cost.

Instead of using liquid ammonia directly, farmers in tropical countries like India prefer to use more stable and user-friendly nitrogen fertilizers such as urea, ammonium sulfate, or ammonium nitrate. These fertilizers provide a controlled release of nitrogen to crops and are safer and easier to handle compared to liquid ammonia. Additionally, they are more cost-effective and readily available in agricultural markets.