Questions

The sodium fusion test, or Lassaigne's test, is used in elemental analysis for the qualitative determination of the presence of foreign elements, namely halogens, nitrogen, and sulphur, in an organic compound. It was developed by J. L. Lassaigne.Silver fluoride is soluble in water and does not precipitate and thus this method cannot be used for detection of fluorine.

Sulfur vulcanisation is a chemical process for converting natural rubber or related polymers into more durable materials by heating them with sulfur. By this they achieve improved elasticity, resilience, tensile strength, viscosity, hardness and weather resistance.

Biogeochemical cycles are crucial to ecosystem function because ::

1. Chemical elements are available in only limited amounts and must be recycled.

2. Nutrients and other life-sustaining molecules are in limited supply and must be continually recycled.

The Great Depression was a severe worldwide economic depression that took place mostly during the 1930s, beginning in the U.S. The timing of the Great Depression varied across nations; in most countries it started in 1929 and lasted until the late-1930s. It was the longest, deepest, and most widespread depression of the 20th century. In the 21st century, the Great Depression is commonly used as an example of how far the world's economy can decline.

Orissa