Chemistry GK Questions Quiz-3

Chemistry GK Questions Quiz-3

Chemistry Multiple Choice Questions (MCQs) Quiz for State and UPSC Civil Services Examinations. Objective Questions on Chemistry for competitive examinations.

    41. The natural source of hydro-carbon is

    (1) Crude oil 
    (2) Biomass
    (3) Coal 
    (4) Carbohydrates
    Answer:
    41. (1) In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called
    hydrocarbyls. Aromatic hydrocarbons (arenes), alkanes, alkenes, cycloalkanes and alkyne-based
    compounds are different types of hydrocarbons. The majority of hydrocarbons found naturally occur in
    crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded, can catenate to form seemingly limitless chains.


    42. Which of the following is chiefly present in LPG (Liquefied Petroleum Gas) ?

    (1) Methane 
    (2) Ethane
    (3) Propane 
    (4) Butane
    Answer:
    42. (4) Liquid petroleum gas is a flammable mixture of hydrocarbon gases used as a fuel in heating
    appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing
    chlorofluorocarbons in an effort to reduce damage to the ozone layer. it has primarily butane (C4H10).


    43. Which one of the following metals is used to galvanise iron ?

    (1) Copper 
    (2) Lead
    (3) Zinc 
    (4) Mercury
    Answer:
    43. (3) Galvanization) is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.


    44. Which of the following is not a precious/semi-precious stone?

    (1) Sapphire 
    (2) Ruby
    (3) Pearl 
    (4) Emerald
    Answer:
    44. (3) A pearl is a hard object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of a clam, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries, and because of this, the word pearl has become a metaphor for something very rare, fine, admirable, and valuable.


    45. Which among the following metals provides amphoteric oxide ?

    (1) Sodium 
    (2) Silver
    (3) Aluminium 
    (4) Calcium
    Answer:
    45. (3) In chemistry, an amphoteric species is a molecule or ion that can react as an acid as well as a base. Many metals (such as zinc, tin, lead, aluminium, and beryllium) and most metalloids form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation state of the oxide. One type of amphoteric species areamphiprotic molecules, which can either donate or accept a proton (H+). Examples include amino acids and proteins, which have amine and carboxylic acid groups, and self-ionizable compounds such as water and ammonia.


    46. Humburger effect is otherwise known as–

    (1) Sodium pump
    (2) Anaerobic metabolism
    (3) Choloride shift
    (4) Respiratory product
    Answer:
    46. (3) Hamburger shift(also known as the Chloride shift) is a process which occurs in the cardiovascular system and refers to the exchange of bicarbonate (HCO3– ) and chloride (Cl–) across the membrane of red blood cells. Carbon dioxide (CO2) generated in tissues enters the blood and dissolves in water in the red blood cells to form carbonic acid (H2CO3), which then dissociates to form bicarbonate (HCO–3) and a hydrogen ion (H+). Here, the exchange of bicarbonate for chloride in red blood cells flushes the bicarbonate from the blood and increases the rate of gas exchange. This chloride shift may also regulate the affinity of hemoglobin for oxygen through the chloride ion acting as an allosteric effector.


    47. Which among the following elements is found in maximum percentage in the human body ?

    (1) Carbon 
    (2) Hydrogen
    (3) Nitrozen 
    (4) Oxyzen
    Answer:
    47. (4) Most of the human body is made up of water, H2O, with cells consisting of 65-90% water by weight. Therefore, it isn’t surprising that most of a human body’s mass is oxygen. Carbon, the basic unit for organic molecules, comes in second. 99% of the mass of the human body is made up of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus.


    48. Which among the following stage is suitable indicator when solution of sodium carbonate is mixed with sulphuric acid ?

    (1) Methylene blue
    (2) Methyl red
    (3) Phenolphthaline
    (4) Methyl orange
    Answer:
    48. (4) Methyl orange is a pH indicator frequently used in titrations. It is often used in titrations because of its clear and distinct colour change. Because it changes colour at the pH of a mid-strength acid, it is usually used in titrations for acids. In a solution becoming less acidic, methyl orange moves from red to orange and finally to yellow with the reverse occurring for a solution increasing in acidity. The entire colour change occurs in acidic conditions. In an acid it is reddish and in alkali it is yellow.


    49 Which among the following is pure matter ?

    (1) Carbon–dioxide
    (2) Brass
    (3) Air
    (4) Iron
    Answer:
    49. (1) Carbon dioxide is a pure substance, provided there is nothing else in it. A “pure substance” does not mean an element. Rather, it means that the given substance has definite physical and chemical properties. “Pure substances” can be either “Elements” or “Compounds” because all substances belonging to these categories have definite physical and chemical properties. A mixture does not have definite physical and chemical properties, and combine in varying proportions.


    50. Which among the following coal contains 90 per cent of carbon?

    (1) Anthracite 
    (2) Bitumen
    (3) Lignite 
    (4) Peat
    Answer:
    50. (1) Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Anthracite contains 90 per cent of carbon.


    51. Bauxite is an alloy of which of the following metals ?

    (1) Aluminium 
    (2) Silver
    (3) Tin 
    (4) Iron
    Answer:
    51. (1) Bauxite is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite Al(OH)3, boehmite -AlO(OH), and diaspore a-AlO(OH), in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO 2. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821.


    52. Nucleus of an atom consists of.

    (1) Proton
    (2) Neutron
    (3) Proton and Neutron
    (4) Electron, Proton and Neutron
    Answer:
    52. (3) The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discovered in 1911, as a result of Ernest Rutherford’s interpretation of the famous 1909 Rutherford experiment performed by Hans Geiger and Ernest Marsden, under the direction of Rutherford. The proton–neutron model of nucleus was proposed by Dmitry Ivanenko in 1932. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the orbiting electrons.


    53. ‘Milk of Magnesia’ is a suspension of :

    (1) magnesium sulphate
    (2) magnesium carbonate
    (3) magnesium hydroxide
    (4) magnesium chloride
    Answer:
    53. (3) Magnesium 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. Magnesium hydroxide is a common component of antacids and laxatives; it interferes with the absorption of folic acid and iron. Magnesium hydroxide has low solubility in water, with a Ksp of 1.5×10–11; however all of the magnesium hydroxide that does dissolve dissociates.


    54. Quartz is made of

    (1) Calcium Sulphate
    (2) Calcium Silicate
    (3) Sodium Sulphate
    (4) Sodium Silicate
    Answer:
    54. (4) Quartz is an abundant mineral in the Earth’s continental crust. It is made up of a continuous
    framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra,
    giving an overall formula SiO2. There are many different varieties of quartz, several of which are semiprecious gemstones. Most quartz used in microelectronics is produced synthetically. Large,
    flawless and un-twinned crystals are produced in an autoclave via the hydrothermal process. The process involves treating crushed natural quartz with hot aqueous solution of a base such as sodium hydroxide.


    55. Which of the following is ozone depleting pesticide ?

    (1) D.D.T.
    (2) Benzene
    (3) Methyl bromide
    (4) Ethylene ozonide
    Answer:
    55. (3) Methyl bromide- is considered to be a significant ozone depleting substance (ODS) by atmospheric scientists. While methyl bromide is a natural substance, the additional methyl bromide added to the atmosphere by humans contributes to the thinning of the ozone layer, allowing increased UV radiation to reach the earth’s surface, with potential impact not only to human health and the environment, but to agricultural crops as well.


    56. Galvanised iron is made by coating iron with

    (1) Zinc 
    (2) Nickel
    (3) Chromium 
    (4) Sulphur
    Answer:
    56. (1) Galvanization) is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.


    57. Isobars are lines joining places having equal

    (1) Rainfall
    (2) Pressure
    (3) Population
    (4) Height above sea-level
    Answer:
    57. (2) An isobar is a line of equal or constant pressure on a graph, plot, or map; an isopleth or contour line of pressure. More accurately, isobars are lines drawn on a map joining places of equal average atmospheric pressure reduced to sea level for a specified period of time. In meteorology, the barometric pressures shown are reduced to sea level, not the surface pressures at the map locations. The distribution of isobars is closely related to the magnitude and direction of the wind field, and can be used to predict future weather patterns.


    58. Global warming is mainly due to accumulation of

    (1) Oxides of nitrogen
    (2) Oxides of sulphur
    (3) Carbon dioxide
    (4) Carbon monoxide
    Answer:
    58. (3) Global Warming refers to average increase in the earth’s temperature due to increase in pollution which results in greenhouse effect which in turn leads to climate change. Global warming may lead to rise in the sea level due to melting of glaciers, shrinkage of forests, changes in the rainfall pattern and wide range of impacts on plants and humans. The greenhouse gases such as carbon dioxide accumulate into the atmosphere and trap heat that would normally exit into the outer space.


    59. Which is abundant in Gobar gas?

    (1) Carbon dioxide
    (2) Methane
    (3) Oxygen
    (4) Hydrogen
    Answer:
    59. (2) Bio gas is a clean unpolluted and cheap source of energy in rural areas. It consists of 55-70% methane which is inflammable. Bio gas is produced from cattle dung in a bio gas plant commonly known as gobar gas plant through a process called digestion. It helps in reducing the deforestation as it arrests for cutting of trees for firewood. It also helps in maintaining ecological balance, in rural sanitation and it needs Lower capital cost and almost cost free maintenance.

    60. The most suitable vessel for storing concentrated sulphuric acid is

    (1) Copper vessel
    (2) Aluminium vessel
    (3) Glass vessel
    (4) Earthen vessel
    Answer:
    60. (3) Concentrated Sulfuric acid can only be stored in glass, no metal lids, some plastic containers. It will attack anything organic, causing severe burns, the good thing is it will not start a fire but if it goes into contact with a metal it may generate hydrogen gas, an explosion risk.


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