Test: Science & Technology- 6 - UPSC MCQ

Beryllium sulfate (BeSO₄) is a white crystalline solid. It was first isolated in 1815 by Jons Jakob Berzelius. Beryllium sulfate may be prepared by treating an aqueous solution of any beryllium salt with sulfuric acid, followed by evaporation of the solution and crystallization. The hydrated product may be converted to anhydrous salt by heating at 400°C. Beryllium Sulphate is less soluble in water due to High inflammable energy.

Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (14C) to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years.

Cements (e.g., Portland cement) harden because of hydration, chemical reactions that occur independently of the mixture’s water content; they can harden even underwater or when constantly exposed to wet weather. The chemical reaction that results when the anhydrous cement powder is mixed with water produces hydrates that are not water soluble. 

If a bond is broken, energy is released; and if a bond is formed, energy must have been absorbed. As these occur, a change in the chemical energy of the system also occurs. Within each bond of a molecule is an experimentally determined amount of energy that upon the breaking of that bond is released into the chemical system. The energy within these bonds are ‘stored’ and can be easily thought of as potential energy. Upon the breaking of these bonds the energy is released thereby creating usable energy. 

Cane-sugar is carbohydrate and as this name implies, is composed of carbon, hydrogen and oxygen. it is a source of extracting sugar. There are various types of sugar derived from different sources. Simple sugars are called monosaccharides and include glucose, fructose and galactose. The table or granulated sugar most customarily used as food is sucrose, a disaccharide. Other disaccharides include maltose and lactose.

Iron ores are rocks and minerals from which metallic iron can be economically extracted. The iron itself is usually found in the form of magnetite (Fe₃O₄), hematite (Fe₂O₃), goethite (FeO(OH), limonite (FeO(OH).n(H₂O)) or siderite (FeCO₃). Hematite, also spelled as haematite, is the mineral form of iron(III) oxide (Fe₂O₃), one of several iron oxides. It is mined as the main ore of iron. Huge deposits of hematite are found in banded iron formations. Gray hematite is typically found in places where there has been standing water or mineral hot springs, such as those in Yellowstone National Park in the United States.

The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions (particles with half-integer spin) may occupy the same quantum state simultaneously. A more rigorous statement is that the total wave function for two identical fermions is anti-symmetric with respect to exchange of the particles. For example, no two electrons in a single atom can have the same four quantum numbers; if n, l, and ml are the same, ms must be different such that the electrons have opposite spins. 

Commercial nitric acid has a brown colour due to dissolved NO₂. The procedure of bubbling dry air through warm commercial nitric acid, is to drive away the dissolved nitrogen dioxide so that the acid becomes colourless.

A growth fertilizer will have a high N content and relatively low P and K content. Ammonium nitrate is the highest Nitrogen fertilizer you can buy, and it is potent stuff. It is usually rated as 33-0-0 or 34-0-0. The bag contains 33% or 34% Nitrogen and the other 66% or 67% is inert material. Other formulations of growth fertilizers will contain 5, 6 or even 7 times more Nitrogen than anything else. 

Since water and carbon dioxide are both compounds which contain oxygen, it is possible to obtain oxygen from either. The oxygen produced from photosynthesis is not released into the air. It is not until cellular respiration that oxygen is released. The oxygen comes from water. The water molecules are split at the “beginning” of photosynthesis for the electrons. These electrons eventually make their way to the electron transport chain, where oxygen is the final electron accept, and then released into the air. Scientists agree that there’s oxygen from ocean plants in every breath we take. Most of this oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. A byproduct of photosynthesis is oxygen.

Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes - a clear indication that the action of ethylene is general and widespread amongst a number of fruits. It is clear that ethylene is a ripening hormone - a chemical substance produced by fruits with the specific biological phenomenon of accelerating the normal process of fruit maturation and senescence.

Fertilizer (or fertiliser) is any organic or inorganic material of natural or synthetic origin (other than liming materials) that is added to a soil to supply one or more plant nutrients essential to the growth of plants. The three elements most needed in common fertilisers are Nitrogen. Potassium and Phosphorous

The history of car pollution has been one of air and water contamination followed by regulated improvement. Cars and trucks cause a lot of air the pollution in the world today, and contribute a lot to the most common and dangerous air pollutants. About 2.3 million tons of lead in lead acid (PbA) batteries is on the road now. Over 1 million tons of lead is used in making new batteries each year. In the past, motor vehicles were the biggest source of lead. But since leaded gasoline has been phased out, lead emissions have decreased by about 98 percent. Today, metal processing is the biggest source of atmospheric lead. The highest air concentrations are found in the vicinity of ferrous and nonferrous smelters and battery manufacturers.

Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO₃. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). Since it has long been known and is widely used, the salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda.

An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).

Carbon dioxide is present under pressure in soft drinks. Carbon dioxide adds that special sparkle and bite to the beverage and also acts as a mild preservative. Carbon dioxide is an uniquely suitable gas for soft drinks because it is inert, non-toxic, and relatively inexpensive and easy to liquefy.

In printing, type metal (sometimes called hot metal) refers to the metal alloys used in traditional type founding and hot metal typesetting. Lead is the main constituent of these alloys. Antimony and tin are added to make the character produced durable and tough while reducing the difference between the coefficients of expansion of the matrix and the alloy. Pure metal melts and solidifies in a simple manner at a specific temperature. This is not the case with alloys.

The actinides (or actinoids) are the chemical elements with atomic numbers between 90 and 109 inclusively. They occur between Groups 3 and 4 in Period 7 of the periodic table. All elements in this family are radioactive. Five actinides namely: thorium, protoactinium, uranium, neptunium, and plutonium have been found in nature. Plutonium is used in the manufacture of nuclear weapons and as the power source in nuclear power plants. On a smaller scale, it is also used as a power source in smaller devices such as the heart pacemaker.

Uranium is used to produce a chemical and nuclear reaction which makes a lot of heat. This heat is used to turn water into steam, which turns turbines...turbines generate electricity.

Table salt is refined salt, which contains about 97 to 99 percent sodium chloride. It usually contains substances that make it free-flowing (anticaking agents) such as sodium aluminosilicate or magnesium carbonate. Because of Hygroscopic nature of salt it become wet in rainy season as the salt absorbs moisture from environment. 

Graphite is used as a lubricant in heavy machines. it is made of carbon atoms arranged in sheets of hexagonal units - looks a lot like chicken-wire. Another sheet forms on top of this and so on. There is no proper connection (in ideal graphite) between the sheets, so they are able to slide freely over each other without breaking any bonds.

A “dry-cell” battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half-reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.

Iodized salt (also spelled iodised salt) is table salt mixed with a minute amount of various salts of the element iodine. Table salt with iodide salt slowly loses its iodine content through the process of oxidation and iodine evaporation. Edible salt can be iodised by spraying it with a potassium iodate solution. 60 ml of potassium iodate.

A colloid is a substance microscopically dispersed evenly throughout another substance. A colloidal system consists of two separate phases: a dispersed phase (or internal phase) and a continuous phase (or dispersion medium) in which the colloid is dispersed. A colloidal system may be solid, liquid, or gas. Milk is an emulsified colloid of liquid butterfat globules dispersed within a water-based solution.

The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.