Chemistry solved MCQs

explanation:-agnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. As a suspension in water, it is often called milk of magnesia because of its milk-like appearance. The solid mineral form of magnesium hydroxide is known as brucite.

explanation:-Dilute sulfuric acid (H2SO4) serves as the electrolyte in a lead storage battery. The electrodes of the cells in a lead storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The opehings of the cathodic grid is filled with lead dioxide (PBO2).

explanation:-Like many other things, milk contains bacteria, Milk also naturally contains a kind of sugar known as "lactose." The bacteria that live in milk get energy from this special sugar and use it to reproduce to make even more bacteria. When the bacteria use the lactose sugars to reproduce, they change it from "lactose sugar" into "lactic acid," which tastes sour.

explanation:-Alizarin or 1,2- dihydroxyanthraquinone (also known as Mordant Red 11 and Turkey Red is an organic compound with formula C14H8O4 that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural pigment to be duplicated synthetically.

explanation:-There are various grades of gold purity, determined by the ratio of their alloy composition and rated by a karat system. Typical karat purities range from 10 karats to 24 karats (pure gold), with a wide variation of usage from country to country, 18 karat gold consists of 75% gold and 25% alloy metals. 18 karat gold has been found to be the perfect balance between gold purity and strength. Brilliance offers a variety of exquisite 18 karat gold jewelry.

explanation:-Neutralization is a process when acids and bases react to form salt and water.

explanation:-Firedamp is flammable gas found in coal mines. It is the name given to a number of flammable gases, especially methane.

explanation:-Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element (by mass) forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. Wrought iron is the purest form of iron. It contains less than 0.25% carbon.

explanation:-An amalgam is a substance formed by the reaction of mercury with another metal. Almost all metals can form amalgams with mercury, notable exception being iron. Silver-mercury amalgams are important in dentistry, and gold-mercury amalgam is used in the extraction of gold from ore. Dentistry has used alloys of mercury with metals such as silver, copper, indium, tin and zinc. Amalgam is an "excellent and versatile restorative material" and is used in dentistry for a number of reasons.

explanation:-Petroleum or crude oil is a naturally occurring flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. A fossil fuel, it is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and undergo intense heat and pressure.

explanation:-A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation.

explanation:-An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions arepart of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working.

explanation:-Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2. 1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten.

explanation:-Breads rise due to the process of fermentation, a chemical process by which molecules such as glucose are broken down an aerobically.

explanation:-The candle can be made of paraffin (a byproduct of petroleum refining), microoystalline wax, stearin (now produced almost exclusively from palm waxes though initially manufactured from animal fats), beeswax (a byproduct of honey collection), gel (a mixture of polymer and mineral oil), some plant waxes (generally palm, carnauba, bayberry, or soybean wax), tallow (rarely used since the introduction of affordable and cheap wax alternatives) or spermaceti (extracted from the head of a Sperm Whale).

explanation:-Nickel silver is a copper alloy with nickel and oft6n. zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong (Cupronickel) All modern, commercially important nickel silvers (such as those standardized under ASTM B 122) contain significant amounts of zinc, and are sometimes considered a subset of brass.

explanation:-The unusually high concentration of oxygen has on Earth is the result of the oxygen cycle. This biogeochemical cycle describes the movement of oxygen within and between itsthree main reservoirs on Earth: the atmosphere, the biosphere, and the lithosphere. The main driving factor of the oxygen cycle is photosynthesis, which is responsible for modern Earth's atmosphere. Photosynthesis releases oxygen into the atmosphere, while respiration and decay remove it from the atmosphere.

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explanation:-Biogas or Lobar gas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops. It comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.

explanation:-Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. It is today mainly used in the kitchen as a general cooking ingredient, but historically, as the most easily available mildacid, it had a great variety of industrial, medical, and domestic uses.

explanation:-Vaseline is a brand of petroleum jelly based products owned by Anglo-Dutch company Unilever. While Vaseline can be used as a lubricant, it is also a useful moisture insulator for local skin conditions characterized by tissue dehydration. Vaseline helps protect minor cuts and burns.

explanation:-A flame test is performed by introducing a sample into the blue flame of a bunsen burner and noting any change in the colour of the flame. The tests can be used to detect the presence of some metallic elements in salts. With strontium salt, the colour of Bunsen flame ranges from crimson to red.

explanation:-Nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a very large amount of energy, even bythe energetic standards of radioactive decay. Fission as encountered in the modern world is usually a deliberately produced manmade nuclear reaction induced by a neutron.

explanation:-A greenhouse has (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.

explanation:-One end of a match is coated with a material that can be ignited by frictional heat generated by striking the match against a suitable surface. The coated end of a match, known as the match "head," contains either phosphorus or phosphorus sesquisulfide as the active ingredient and gelatin as a binder.