Test: Chemistry- 2 - Railways MCQ

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.

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.

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 by the energetic standards of radioactive decay. Fission as encountered in the modern world is usually a deliberately produced manmade nuclear reaction induced by a neutron.

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.

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.

The main source of Naphthalene is coal-tar. Naphthalene is derived from a kind of naphtha which is a broad term encompassing any volatile, namable liquid hydrocarbon mixture, including coaltar. 

A solar cell (also called a photovoltaic cell) is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. Materials presently used for photovoltaic solar cells include mono-crystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper iridium selenide/sulfide.

Quartz is made up of a continuous framework of SiO₄ silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO₂. Tridymite and cristobalite are hightemperature polymorphs of SiO₂ that occur in high-silica volcanic rocks. Coesite is a denser polymorph of quartz found in some meteorite impact sites and in metamorphic rocks.

In order to give more strength and more elasticity, natural rubber is heated with sulphur or sulphur compounds at 150°C temperature. Vulcanized rubber has good tensile strength.

More than 90% of world production of urea is destined for use as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use.

During interconversion of energy from one form to other forms, total energy at any time remains constant.

Sublimation is a type of phase transition, or a change in a state of matter, just like melting, freezing, and evaporation.

Seaweed is a source of iodine, necessaly for thyroid function and to prevent goitre. However, an excess of iodine is suspected in the heightened cancer risk in Japanese who consume a lot of the plant, and even bigger risks in post-mempausal women.

Hydrogen is used to manufacture vanaspati from vegetable oil.

The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, the solution turns more basic.

The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.

A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutiops." These substances are usually alkylbenzenesulfonates, a family of compounds that are similar to soap but are more soluble in hard water, because the polar sulfonate (of detergents) is less likely than the polar carboxyl (of soap) to bind to calcium and other ions found in hard water. In most household contexts, the term detergent by itself refers specifically to laundry detergent or dish detergent, as opposed to hand soap or other types of cleaning agents.

An early-20^th-century form of quackery was the treatment of maladies in a radiotorium. It was a small, sealed room for patients to be exposed to radon for its "medicinal effects". The carcinogenic nature of radon due to its ionizing radiation became apparent later on. Radon's molecule-damaging radioactivity has been used to kill cancerous cells. It does not, however, increase the health of healthy cells. In fact, the ionizing radiation causes the formation of free radicals, which results in genetic and other cell damage, resulting in increased rates of illness, including cancer.

A rectified spirit, rectified alcohol, or neutral spirit is highly concentrated ethanol which has been purified by means of repeated distillation, a process that is called rectification. It typically contains 95% alcohol by volume (ABV). Rectified spirits are used in mixed drinks, in the production of liqueurs, for medicinal purposes, and as a household solvent.

Bauxite is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO₂. Bauxite was named after the village Les Baux in southern France, where it was first recognized as containing aluminium and named by the French geologist Pierre Berthier in 1821.