Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure and composition. Although the words “oils”, “fats”, and “lipids” are all used to refer to fats, “oils” is usually used to refer to fats that are liquids at normal room temperature, while “fats” is usually used to refer to fats that are solids at normal room temperature. Fats also serve as energy stores for the body, containing about 37.8 kilojoules (9 calories) per gram of fat. They are broken down in the body to release glycerol and free fatty acids. The glycerol can be converted to glucose by the liver and thus used as a source of energy.

Correct Option: B

Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure and composition. Although the words “oils”, “fats”, and “lipids” are all used to refer to fats, “oils” is usually used to refer to fats that are liquids at normal room temperature, while “fats” is usually used to refer to fats that are solids at normal room temperature. Fats also serve as energy stores for the body, containing about 37.8 kilojoules (9 calories) per gram of fat. They are broken down in the body to release glycerol and free fatty acids. The glycerol can be converted to glucose by the liver and thus used as a source of energy.

Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for determining this amount. This is not a precise quantitative test, although it is widely used as an indication of the organic quality of water. The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 degree C and is often used as a robust surrogate of the degree of organic pollution of water.

Correct Option: B

Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for determining this amount. This is not a precise quantitative test, although it is widely used as an indication of the organic quality of water. The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 degree C and is often used as a robust surrogate of the degree of organic pollution of water.

Aluminum powder is a highly flammable powder created by grinding aluminum into fine grains of material. In times past, this flammable metal powder was used in photography to create bright flashes during a photographic session. Today, aluminum powder is one of the tools utilized in various applications of pyrotechnics, including the creation of fireworks displays. Used primarily as an inlay compound, the aluminum powder can easily be used to set cut pieces of wood into position and also fill in any tiny gaps that may be present at the joints. Since only a minute amount of powder is necessary for functions of this type, the chances of ignition are somewhat limited.

Correct Option: C

Aluminum powder is a highly flammable powder created by grinding aluminum into fine grains of material. In times past, this flammable metal powder was used in photography to create bright flashes during a photographic session. Today, aluminum powder is one of the tools utilized in various applications of pyrotechnics, including the creation of fireworks displays. Used primarily as an inlay compound, the aluminum powder can easily be used to set cut pieces of wood into position and also fill in any tiny gaps that may be present at the joints. Since only a minute amount of powder is necessary for functions of this type, the chances of ignition are somewhat limited.

Quartz sand (silica) is the main raw material in commercial glass production. While fused quartz (primarily composed of SiO2) is used for some special applications, it is not very common due to its high glass transition temperature of over 1200 degree C (2192 degree F). Normally, other substances are added to simplify processing. One is sodium carbonate (Na2CO3, “soda”), which lowers the glass transition temperature. However, the soda makes the glass water soluble, which is usually undesirable, so lime (calcium oxide [CaO], generally obtained from limestone), some magnesium oxide (MgO) and aluminium oxide (Al2O3) are added to provide for a better chemical durability. The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass.

Correct Option: A

Quartz sand (silica) is the main raw material in commercial glass production. While fused quartz (primarily composed of SiO2) is used for some special applications, it is not very common due to its high glass transition temperature of over 1200 degree C (2192 degree F). Normally, other substances are added to simplify processing. One is sodium carbonate (Na2CO3, “soda”), which lowers the glass transition temperature. However, the soda makes the glass water soluble, which is usually undesirable, so lime (calcium oxide [CaO], generally obtained from limestone), some magnesium oxide (MgO) and aluminium oxide (Al2O3) are added to provide for a better chemical durability. The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass.

Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops. Biogas comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.

Correct Option: A

Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops. Biogas comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.