Question

A small amount of a foul smelling gaseous organic sulphur compound is added to the commercial LPG for leak detection. The property of this gas which helps in leak detection is (1) Sublimation (2) Molecular vibration (3) Molecular association (4) Diffusion

Short answer

4. Diffusion

Step-by-step solution

Understanding the Question

The question asks for the property of the gas added to LPG for leak detection. This gas is foul-smelling and helps in identifying leaks.

Analyzing Options

Consider each property:1. Sublimation - This is the transition of a substance from solid to gas without going through a liquid state.2. Molecular vibration - This involves the oscillation of atoms within molecules, typically associated with infrared spectroscopy.3. Molecular association - This refers to the formation of complexes between molecules.4. Diffusion - This is the process by which molecules spread from areas of high concentration to low concentration.

Identifying Relevant Property

Leak detection relies on the gas spreading throughout the area, so the property that enables this is diffusion.

Conclusion

The property that helps in leak detection is diffusion because it causes the gas to spread rapidly, making it detectable by smell.

Key concepts

Diffusion Process

Diffusion is a crucial concept in understanding how gases spread out. It involves the movement of molecules from areas of high concentration to areas of low concentration.
This movement continues until the molecules are evenly distributed throughout the available space. When a small amount of a foul-smelling sulphur compound is added to LPG, this process helps in leak detection.
If there's a leak, the gas will diffuse into the surrounding air, spreading the odor. This makes it easier to detect the leak quickly and take necessary actions to fix it.
In summary, diffusion is the key property that assists in the identification of gas leaks by helping the detection smell to spread easily.

Chemical Detection Methods

Chemical detection methods in LPG systems are vital for safety. These methods often involve adding substances that have certain detectable properties.
In the context of LPG leak detection, organic sulphur compounds are added because they have a strong and unpleasant smell. Below are some important points:

• The added chemical should be easily detectable even in small amounts.
• The chemical should not react harmfully with LPG or its environment.
• It should help in early detection to prevent possible hazards.

In essence, chemical detection methods rely on the idea that certain added substances can act as markers or signals, alerting us to the presence of the LPG in the event of a leak.

Organic Sulphur Compounds

Organic sulphur compounds are used in LPG leak detection because of their strong, foul odor. These compounds contain sulphur in organic molecular structures, which makes them ideal for this purpose.
Let's look at some key characteristics:

• They have a distinct smell even in very low concentrations, making them highly noticeable.
• They are chemically stable, meaning they don't frequently react or break down.
• Common examples include mercaptans and thiols, which are effectively used in many safety applications.

Organic sulphur compounds are thus crucial in ensuring that LPG leaks are quickly and accurately detected, helping to maintain safety.