Anhydrous ammonia is widely used in industrial refrigeration applications. Which among the following is / are the properties of Ammonia that make it a useful chemical?
1. Ammonia is Non-toxic
2. Ammonia has a high dipole moment
3. Ammonia has high heat of vaporization
4. Ammonia is non-corrosive to copper alloys
Choose the correct option from the codes given below:

Answer: [C] Only 2 & 3

Ammonia is a colourless gas with a characteristic pungent smell similar to human urine, as urine decomposes to release ammonia.

It is lighter than air, its density being 0.589 times that of air. It is easily liquefied due to the strong hydrogen bonding between molecules; the liquid boils at -33.3 °C, and solidifies at -77.7 °C to a mass of white crystals. Liquid ammonia has a very high standard enthalpy change of vaporization and that is why can be used in laboratories in non-insulated vessels at room temperature, even though it is well above its boiling point.

Because of ammonia’s vaporization properties, it is a useful refrigerant. It was commonly used prior to the popularisation of chlorofluorocarbons (Freons). Anhydrous ammonia is widely used in industrial refrigeration applications and hockey rinks because of its high energy efficiency and low cost. However, it suffers from the disadvantages of toxicity which restrict its domestic and small scale use. Along with its use in modern vapor-compression refrigeration it was used in a mixture along with hydrogen and water in absorption refrigerators. The Kalina cycle, which is of growing importance to geothermal power plants, depends on the wide boiling range of the ammonia-water mixture.

This question is a part of GKToday's Integrated IAS General Studies Module