What is called ‘black gold’? A.Hydrocarbons B.Coal C.Petroleum D.Ether

The substance which is called black gold is available in earth’s crust but is not abundant. It is referred to gold due to its high worth. It is a common fossil fuel. Complete step by step answer: -As we can understand from the name itself, the substance which is called black gold is black in colour. -As we know, gold is a noble, scarcely available and an expensive metal similarly, black gold is also referred to as gold due to its price and value. -The term Black Gold is used to refer to oil or petroleum. -Petroleum is a naturally occurring yellowish-black liquid found beneath the Earth’s surface. -It is generally refined and various fuels are formed from it. -It consists of naturally occurring hydrocarbons of different molecular weights but it also contains some other organic compounds. Each petroleum variety has a unique mixture of molecules which defines its physical property like colours, density and viscosity. -The name petroleum is referred to both naturally occurring crude oil and also the petroleum products which are formed from the crude oil. -Petroleum is called ‘Black Gold’ due to the following reasons- -When petroleum is extracted from the ground, the crude oil is black in colour. -It is compared to gold due to its high commercial value and due to its valuable properties. -It is rare on earth and not easily found. -Its extraction is also very expensive. -The extracted crude oil is black but after purification, it turns yellowish hence the name gold. Therefore, the correct answer is option C petroleum. Additional information The use of petroleum as a fuel increased global warming. It is a major cause for ocean acidification too. Note: It is important to remember here that it has no similar chemical or physical properties as gold. It is also not a metal like gold. It is called black gold simply due to its commercial value. Coal is also black and a common source of fuel but the term ‘black gold’ is not used for coal, it is used for petroleum.