Chemistry Quiz 6

Peat contains recognisable traces of the original plant material. Peat is a soft, organic material consisting of partly decayed plant and mineral matter. When peat is placed under high pressure and heat, it undergoes physical and chemical changes (coalification) to become coal.

Anthracite is the highest grade and best equality coal. It is a hard, very low content of volatile compact variety of coal that has a high luster. It has the highest carbon content (92.1% to 98%), the fewest impurities, and the highest calorific content.

The natural source of hydrocarbon is Crude oil. A hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Crude oil is a mixture of hydrocarbons that exists as a liquid in underground geologic formations.

Ozone consists of oxygen only. It is a triatomic, molecule, consisting of three oxygen atoms. The formula for ozone is O₃. Ozone in the upper atmosphere protects living organisms by preventing damaging ultraviolet light from reaching the Earth's surface.

Cement in different types is made mainly by calcining a mixture of about 75% limestone and 25% clay to form a calcium silicate clinker which is then ground and mixed with a small amount of gypsum.

Aluminium provides amphoteric oxide. Metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides. Many metals (such as zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Al₂O₃ is an example of an amphoteric oxide.

Oxyacetylene flame is commonly known as gas welding. It is a process which relies on combustion of oxygen and acetylene. When mixed together in correct proportions within a hand-held torch or blowpipe, a relatively hot flame is produced with a temperature of about 3200°C.

Ruby and sapphire are precious gemstones, made of Aluminium Oxide (Al₂O₃) with trace amounts of elements such as iron, titanium, chromium, vanadium, or magnesium.

The atomic clock is based on transitions in Caesium. The caesium atomic clock is the most accurate type of clock yet developed. This device makes use of transitions between the spin states of the cesium nucleus and produces a frequency which is so regular that it has been adopted for establishing the time standard.

Transboundary pollution is the pollution that originates in one country but is able to cause damage to another country's environment, by crossing borders through pathways like water or air. It is caused by a chemical reaction that begins when compounds like sulphur dioxide (SO₂) and nitrogen oxides (NO_x) are released into the air. Acid rain is an example of Transboundary pollution.