Question

What is the term used when the rain water has pH less than $5.6$?

Answer 1

We know that Acid Rain as the name recommends can be supposed to be the precipitation of acid as rain in the most straightforward way. At the point when barometrical contaminations like oxides of nitrogen and sulfur respond with water and catch the rain, then, at that point these outcomes in Acid Rain.

Complete answer:
We need to know that the water with a pH under $5.6$ is called Acid rain. Ordinary, clean rain has a pH worth somewhere in the range of $5.0$ and $5.5$ , which is marginally acidic. At the point when sulfur dioxide and nitrogen oxides are delivered into the air, they respond with water and oxygen and produce sulphuric and nitric acids. Along these lines it structures acid rain.

Note:
As we know, the expression "acid rain" is generally used to mean the testimony of acidic segments in rain, snow, mist, dew, or dry particles. The more exact term is "acid precipitation." Distilled water, which contains no carbon dioxide, has an impartial pH of $7$ . Fluids with a pH under $7$ are acidic, and those with a pH more prominent than 7 are basic (or fundamental). "Clean" or unpolluted rain has a somewhat acidic pH of $5.6$, in light of the fact that carbon dioxide and water noticeable all around respond together to frame carbonic acid, a frail acid. Around Washington, D.C., notwithstanding, the normal rain pH is somewhere in the range of $4.2$ and$4.4$.
The additional aridity in rain comes from the response of air poisons, basically sulfur oxides and nitrogen oxides, with water noticeable all around to shape solid acids (like sulfuric and nitric acid). The fundamental wellsprings of these toxins are vehicles and modern and force creating plants. In Washington, the primary nearby sources are vehicles, trucks, and buses.