Practice MCQ Questions and answers on Chemistry-GK

The upper atmosphere derives most of its energy by direct absorption of solar electromagnetic energy in the ultraviolet and X-ray regions of the spectrum.

Sulphur dioxide level in the atmosphere can be reduced by using low sulphur fuels.

Photochemical smog which is mainly composed of ozone (O₃), Peroxyacetyl nitrate (PAN) and Nox, is also known as brown air where solar radiation is intense. In seasons of lesser solar radiation or areas, smog formation is incomplete and the air is referred to as grey air.

The sewage obtained from water closets and urinals in known as Sanitary waste.

Nitrogen is not a Green House gas.

Hydrogen is not a greenhouse gas.

Biogas differs from natural gas in that it is a renewable energy source produced biologically through anaerobic digestion rather than a fossil fuel produced by geological processes. Biogas is primarily composed of methane gas, carbon dioxide, and trace amounts of nitrogen, hydrogen, and carbon monoxide.

LD stands for "Lethal Dose". LD50 is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material.

Carbon monoxide is the major harmful gas emitted by the automobile vehicles which causes air pollution. Carbon monoxide (CO) - A product of incomplete combustion, carbon monoxide reduces the blood’s ability to carry oxygen; overexposure (carbon monoxide poisoning) may be fatal. Carbon Monoxide poisoning is a major killer. Carbon monoxide is a temporary atmospheric pollutant in some urban areas, chiefly from the exhaust of internal combustion engines (including vehicles, portable and back-up generators, lawn mowers, power washers, etc.), but also from incomplete combustion of various other fuels (including wood, coal, charcoal, oil, paraffin, propane, natural gas, and trash). Carbon monoxide is, along with aldehydes, part of the series of cycles of chemical reactions that form photochemical smog