HPSC Exam: MCQ Series Chemistry-III

Chemistry Multiple Choice Questions For HCS Exam

Haryana Civil Services Exam 2020

Important 20000 MCQ Series For HCS Exam: CHEMISTRY PART-III

Q1. The liquid waste from kitchens and baths, of residences, is known as:

(a) Domestic sewage

(b) Storm water

(c) Sullage  

(d) Refuse

Explanation: Sullage is all wastewater generated in households or office buildings from streams without fecal contamination, i.e. all streams except for the wastewater from toilets. Sources of sullage include, e.g. sinks, showers, baths, clothes washing machines or dish washers.

Q2. Which of the following metals form an amalgam with other metals?

(a) Lead  

(b) Tin

(c) Zinc

(d) Mercury

Explanation: Mercury forms an amalgam with other metals.

Q3.The isotope used for the production of atomic energy is 

(a) U-235

(b) U-238

(c) U-234

(d) U-236

Explanation: The isotope U-235 is important because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be 'fissile' and we use the expression 'nuclear fission'. Meanwhile, like all radioactive isotopes, they decay.

Q4.  Which of the following is not a nucleon?

(a) Proton

(b) Neutron

(c) Electron

(d) Positron 

Explanation: Nucleon is one of the particles that makes up the atomic nucleus. Each atomic nucleus consists of one or more nucleons, and each atom in turn consists of a cluster of nucleons surrounded by one or more electrons. There are two kinds of nucleon: the neutron and the proton. The mass number of a given atomic isotope is identical to its number of nucleons. Thus the term nucleon number may be used in place of the more common terms mass number or atomic mass number. Until the 1960s, nucleons were thought to be elementary particles, each of which would not then have been made up of smaller parts. Now they are known to be composite particles, made of three quarks bound together by the so-called strong interaction. The interaction between two or more nucleons is called inter-nucleon interactions or nuclear force, which is also ultimately caused by the strong interaction. (Before the discovery of quarks, the term “strong interaction” referred to just inter-nucleon interactions.)

Q5.  Beryllium Sulphate is less soluble in water due to

(a) High inflammable energy

(b) Low Energy of dissociation

(c] Low inflammable energy

(d) Ionic bond

Explanation: Beryllium Sulphate is less soluble in water due to high inflammable energy.

Q6. What is the name of that system, which uses radioactivity to decide the period of materials of pre-historic period?

(a) Radium dating

(b) Uranium dating

(c) Carbon dating

(d) Deuterium dating

Explanation: Radiometric dating, radioactive dating, or radioisotope dating is a technique that is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. Also known as Carbon dating.

Q7. Cement is made hard with

(a) dehydration

(b) hydration and dissociation of water 

(c) Dissociation of water

(d) Polymerization

Explanation: 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 watersoluble.

Q8. Which among the following is a carbohydrate?

(a) Nylon

(b) Cane-sugar

(c) Turpentine

(d) Hydrogen peroxide

Explanation: 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.

Q9. In which of the following states maximum iron ore is found?

(a) Fe CO3

(b) Fe2O3

(c) Fe3O4

(d) FeS2 

Explanation: 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.

Q10. “All the four quantum numbers of two electrons in an atom are not the same," It is the law of —

(a) Hund’s  

(b) Exclusion Principle of Pauli

(c)Uncertainty Principle of Heisenberg

(d) Avogadro’s Law

Explanation: 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.

Q11.Commercial nitric acid is coloured because it contains dissolved :

(a) Oxygen

(b) Nitrous oxide

(c) Nitrogen dioxide

(d) Coloured impurities 

Explanation: 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.

Q12.Fertilizer having high nitrogen content is:

(a) Urea

(b) Ammonium sulphate

(c) Ammonium nitrate

(d) Calcium citrate  

Explanation: 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.

Q13.Where does the oxygen that keeps us alive come from?

(a) Carbon dioxide

(b) Carbonates absorbed from soil

(c) Oxides of minerals

(d) Water 

Explanation: 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.

Q14.The gas used for artificial fruit ripening of green fruit is—

(a) Ethylene  

(b) Acetylene

(c) Ethane

(d) Methane

Explanation: Calcium carbide is also used in some countries for artificially ripening fruit. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is similar in its effects to the natural ripening agent, ethylene.

Q15.The three elements most needed in common fertilizers are:

(a) Sulphur, Phosphorus and Sodium

(b) Nitrogen, Potassium and Phosphorous

(c) Phosphorus, Sodium and Nitrogen

(d) Calcium, Phosphorus and Potassium

Explanation: 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 fertilizers are Nitrogen. Potassium and Phosphorous

Q16.Which one of the following metals pollutes the air of a city having large number of automobiles?

(a) Cadmium

(b) Chromium

(c) Lead

(d) Copper

Explanation: 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.

Q17.What is the chemical name for 'baking soda’?

(a) Sodium carbonate

(b) Sodium hydrogen carbonate

(c) Sodium nitrite

(d) Sodium nitrate 

Explanation: 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.

Q18. An atomic pile is used for

(a) producing X-rays

(b) conducting nuclear fission

(c) conducting thermonuclear fusion

(d) accelerating atoms

Explanation: 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).

Q19.Which of the following gases is present under pressure in soft drinks?

(a) Oxygen

(b) Nitrogen

(c) Carbon dioxide

(d) Nitrous oxide

Explanation: 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.

Q20.The substance which does not expand on going from liquid state to solid state is

(a) Water

(b) Cast-iron

(c) Aluminium

(d) Type metal

Explanation: 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.

Q21.The advantage of detergents over soaps is

(a) Detergents are soluble in water

(b) Detergents could not give much lather

(c) Detergents give lather even with hard water

(d) Soaps give lather with only soft water

Explanation: Soaps are made of materials found in nature. Detergents are synthetic. a big drawback of washing with soap is that the minerals in water react with those in soap, leaving an insoluble film. Detergents react less to minerals in water and for all practical purposes are the product of choice for laundry, unless you have very soft water. On the other hand, soap will combine with the magnesium and calcium ions in hard water to create an insoluble residue that can clog drains and stick to clothing.

Q22.The fundamental particles present in the nucleus of an atom are 

(a) Electron, proton

(b) Proton, neutron

(c) Neutron, electron

(d) Neutron, positron

Explanation: 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. 

Q23.Bleaching action of moist sulphur dioxide is because of its

(a) basic property

(b) acidic property

(c) oxidising property

(d) reducing property

Explanation: In moist conditions, sulphur dioxide is a bleaching agent. In the reducing action of SO2, oxygen is removed from coloured dye. Sulphur dioxide is used to bleach wool and silk. Salts of sulphur dioxide are also used in bleaching. Calcium hydrogen sulphite Ca(HSO3)2 is used to whiten wood pulp in the manufacturing of paper. Other than SO2, sodium hydrosulphite (Na2S2O4) is also used to bleach wool. However, bleaching using SO2 is not permanent. On exposure to air and light, the original colour slowly returns as oxygen in air oxidises the bleached substance.

Q24.The long range potential of nuclear energy in India depends on its reserves of

(a) thorium

(b) uranium

(c) plutonium

(d) radium

Explanation: India’s domestic uranium reserves are small and the country is dependent on uranium imports to fuel its nuclear power industry. Since early 1990s, Russia has been a major supplier of nuclear fuel to India. Due to dwindling domestic uranium reserves, electricity generation from nuclear power in India declined by 12.83% from 2006 to 2008. Large deposits of natural uranium, which promises to be one of the top 20 of the world’s reserves, have been found in the Tummalapalle belt in the southern part of the Kadapa basin in Andhra Pradesh in March 2011.

Q25.Which of the following gases will effuse out of football bladder most quickly?

(a) He  

(b) H2

(c) N2

(d) 02

Explanation: Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H1) is the most abundant chemical substance, constituting roughly 75% of the Universe’s baryonic mass. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds.

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