Chemistry Exam Modules

SECTION-A 1. The element that exhibits negative oxidation state in IIIA group elements is(1) B (2) Al(3) Ga (4) Tl 2. Boron halides are(1) Electron efficient compounds(2) Ionic compounds(3) Lewis bases(4) Used as refractory compounds 3. Inorganic graphite is(1) (BN)n (2) BF4(3) B2H6 (4) B2N2H6 4. Which of the following is the correct formula of borax?(1) Na2[B4O5(OH)4]. 2H2O(2) Na2[B4O5(OH)4]. 4H2O(3) Na2[B4O5(OH)4].6H2O(4) Na2[B4O5(OH)4].8H2O5. Borax glass is a mixture of(1) NaBO2 + B2O3 (2) Na2B4O7+B2O3(3) H2B4O7 + B2O3 (4) Na2B4O7.10H2O+B2O3 6. Boric acid is prepared from borax by the action of(1) HCl (2) NaOH(3) CO2 (4) Na2CO3 7. Orthoboric acid (H3BO3) and

1. Which of the following animals yields wool? a) Yak b) Goat c) Both (a) and (b) d) None of the above Answer: c 2. _______ phase requires a lot of feeding. a) Caterpillar b) Larva c) Both (a) and (b) d) None of the above Answer: c 3. Which state is a leading producer of wool? a) Himachal Pradesh b) Punjab c) Haryana d) None of the above Answer: b 4. Which of the following is an animal fibre? a) Wool b) Silk c) Both (a) and (b) d) None of the above Answer: c 5. _______ is responsible for Sorter’s disease. a)

Q-1: Which of the following is a friend of the farmer? a) Redworms b) Earthworms c) Moths d) Mosquitoes Answer: b) Earthworms Q-2: Which of the following is the method of preparing compost with the help of redworms? a) Recycling b) Vermicomposting c) Composting d) Both b) and c) Answer: b) Vermicomposting Explanation: The process of converting kitchen garbage into compost with the help of redworms is known as vermicomposting. Q-3: Which of the following helps the redworms to grind their food? a) Teeth b) Gizzard c) Mouth d) Hands Answer: b) Gizzard Explanation: Redworms do not have teeth. They have a structure called ‘gizzard’, which

1. The gas plants use for respiration is: a.) Oxygen b.) Carbon dioxide c.) Nitrogen d.) All of the above Answer – (a.) Oxygen Explanation – The diffusion process allows oxygen from the air to enter a leaf through the stomata and reach all cells. This oxygen is used in the respiration of leaf cells. 2. Which of the following components of air is harmful to living beings? a.) Nitrogen and oxygen b.) Carbon dioxide and water vapour c.) Smoke and water vapour d.) Dust and smoke Answer – (d.) Dust and smoke Explanation – Breathing in smoke and dust can enter our respiratory system (lungs)

1. Which of the following is a source of freshwater? a.) Groundwater b.) Rainwater c.) Surface run-off d.) All of the above Answer – (d.) All of the above Explanation – Freshwater is water that occurs naturally on Earth’s surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers, and streams, as well as underground aquifers and underground streams. 2. Heavy rainfalls lead to: a.) Drought b.) Earthquake c.) Landslides d.) Floods Answer – (d.) Floods Explanation – Heavy rainfalls lead to a rise in the level of water in rivers, lakes and ponds. This water spreads over large areas causing floods. Drought occurs

Q-1: Which of the following is a change that can be reversed? a) Batter to Idli b) Grain to its flour c) Milk to paneer d) Stretched rubber band to its normal size Answer: d) Stretched rubber band to its normal size Explanation: The changes that can be reversed are those that, after taking place, can regain their original shape and size. Because the rubber band can return to its original shape after stretching, the change is reversible. While all other changes are irreversible. Q-2: Which of the following changes that occur in our bodies is reversible? a) Increase in height b) Decrease

1. The process by which butter can be separated from milk is ____. a.) Sedimentation b.) Decantation c.) Filtration d.) Churning Answer – (d.) Churning Explanation – Churning is the process of continuously moving milk or curd with skimmers to produce butter. 2. Which of the following processes can be used to separate a liquid from an insoluble solid? a.) Evaporation b.) Sedimentation c.) Distillation d.) Filtration Answer – (d.) Filtration Explanation – Filtration is the process of separating suspended solid matter from a liquid by passing it through the pores of a membrane known as a filter. For example, tea leaves are separated from tea

Class 6 Sorting Materials Into Groups MCQs   1. Which of the following materials is transparent? a.) Stainless steel plate b.) Glass tumbler c.) Mirror d.) Plastic bottle Answer – (b.) Glass tumbler Explanation – Almost all the light that strikes transparent materials passes directly through them. In stainless steel, mirror and plastic bottles, light cannot pass through them, and they are therefore not considered transparent.   2. From the given options, choose the one that does not belong to the group. a.) Milk b.) Honey c.) Oil d.) Ink Answer – (c.) Oil Explanation – Milk, honey and ink can dissolve in water, but oil

1. Which one of the following is a synthetic fibre? a.) Rayon b.) Nylon c.) Polyester d.) All of the above Answer – (d.) All of the above Explanation – Synthetic fibres are man-made polymers that are used to create fabric. Polymers are formed when many small units are chemically joined together.   2. The process of separating cotton fibres from the seeds is called ____. a.) Retting b.) Ginning c.) Weaving d.) Spinning Answer – (b.) Ginning Explanation – Ginning is the process of separating cotton fibres from cotton seeds or lint. It also aids in the removal of

1. For medicinal chemists, the classification of medications based on is the most useful.a) pharmacological effectb) molecular targetsc) chemical structured) drug action Answer: bExplanation: Medicinal chemists are interested in the site where a drug will take effect, and they prescribe specific drugs to people based on their needs. This also includes the structure-based mechanism of pharmacological action on the target. 2. Which of the following medications is not classified according to the pharmacological effect criteria?a) Analgesicsb) Antisepticsc) Antihistaminesd) Antipyretics Answer: cExplanation: The pharmacological effects of medications are a group of drugs that all have the same effect on a specific

1. Any substance made up of multiple repeating units called polymers is referred to as a polymer.a) Mersb) Plasticc) Resinsd) Blocks Answer: aExplanation: Any substance made up of multiple repeating units, known as mers, is referred to as a polymer. Polymers are made up of a large number of molecules connected together to form long chains. 2. Which of the following polymers does not fall within the configuration category?a) Cross-linkedb) Atacticc) Syndiotacticd) Isotactic Answer: aExplanation: The category of configuration does not include cross-linked polymers. The categories of configuration include syndiotactic, atactic, and isotactic. Within a macromolecule, tacticity refers to the

1. A disaccharide is formed when two monosaccharides are bonded together by a bond.a) glycosidicb) peptidec) ionicd) phosphodiester Answer: aExplanation: When two monosaccharide units come together, they lose a molecule of water and form an oxide bond. The glycosidic linkage is a bond formed by an oxygen atom between two monosaccharide molecules. 2. Sucrose is a _____ chemical, and the hydrolysis product combination is ______in nature.a) dextrorotatory; dextrorotatoryb) laevorotatory; laevorotatoryc) laevorotatory; dextrorotatoryd) dextrorotatory; laevorotatory Answer: dExplanation: Sucrose is a dextrorotatory sugar that produces a combination of dextrorotatory glucose and laevorotatory fructose when hydrolyzed. The resultant mixture is laevorotatory because the

1. What is the most basic aromatic amine’s common name?a) Benzenamineb) Benzylaminec) Anilined) Aminobenzene Answer: cExplanation: The simplest amine is aniline, which has the formula C6H5NH2. This name is also recognised by the IUPAC. The IUPAC designation for it is benzenamine, although it’s also known as aminobenzene. 2. What is the correct name for a molecule that has two amino groups in opposing (para) locations around a benzene ring?a) Benzenediamineb) Benzene-1,4-diaminec) p-Aminoanilined) 4-Aminobenzenamine Answer: bExplanation: Both amino groups (in para positions to one other) are given equal weight and the primary complex is given the prefix di. The prefix is

1. Which of the reactions below can result in ketones?a) Oxidation of primary alcoholsb) Oxidation of secondary alcoholsc) Dehydrogenation of tertiary alcoholsd) Dehydrogenation of primary alcohols Answer: bExplanation: Ketones are formed when secondary alcohols are oxidised and dehydrogenated. Aldehydes are produced by the same processes with primary alcohols. 2. The Rosenmund reaction can produce which of the following carbonyl compounds?a) Methanalb) Benzaldehydec) Butanoned) Acetone Answer: bExplanation: The Rosenmund reaction, which involves replacing chloride with hydrogen, is only utilised to make aldehydes. Methanal cannot be produced from this process because the acyl chloride that corresponds to it, formyl chloride, is unstable

1. To get carboxylic acids directly from alcohol, which of the following oxidising agents is used?a) Alkaline KMnO4b) Aqueous KMnO4c) Acidified KMnO4d) Anhydrous CrO3 Answer: cExplanation: Strong oxidizers, such as acidified potassium permanganate or acidified potassium dichromate, convert alcohol to carboxylic acid immediately. Using CrO3 as the oxidising agent in an anhydrous media, however, only aldehyde can be produced. 2. When phenol reacts with bromine water, what is the result?a) Brown liquidb) Colourless gasc) White precipitated) No reaction Answer: cExplanation: When phenol is treated with bromine water, a white precipitate is formed, which is 2,4,6-Tribromophenol. 3. The Lucas test was carried

1. What is the class of the substitution product of LiAlH4 and an alkyl halide reaction?a) Haloalkaneb) Alkyl nitritec) Nitroalkaned) Hydrocarbon Answer: dExplanation: The H atom in LiAlH4 acts as a nucleophile, attacking and substituting the halogen in the alkyl halide to generate the basic hydrocarbon. 2. Which of the following statements about SN2 mechanisms is incorrect?a) The transition state is stableb) The complete mechanism takes place in a single stepc) The rate of the reaction depends on the concentration of both reactantsd) There is an inversion of configuration Answer: aExplanation: The carbon atoms are concurrently attached to the entering nucleophile and the

1. A coordination complex’s core atom/ion is also known as ________a) Bronsted-Lowry acidb) Lewis basec) Lewis acidd) Bronsted-Lowry base Answer: cExplanation: A Lewis acid is a species that has the ability to receive an electron pair. Lewis acids are all cations. It is a Lewis acid because the core atom of a coordination complex is metal and always accepts electrons. 2. Which of the following has a coordination number as a feature?a) Coordination entityb) Ligandc) Central atomd) Coordination compound Answer: cExplanation: The coordination number of a central metal ion in a complex, also known as the secondary valency, is defined as the

1. As an electroplated protective covering, what metal is used?a) Plutoniumb) Chromiumc) Nickeld) Iron Answer: bExplanation: Chrome plating (or chromium plating, as it’s more generally known) is the process of electroplating a thin layer of chromium onto a metal item. The chromed coating might be attractive, provide corrosion protection, make cleaning easier, or increase the hardness of the surface. 2. __________ possesses the properties of both alkali metals and halogens.a) Heliumb) Hydrogenc) Sodiumd) Chlorine Answer: bExplanation: Because hydrogen’s outer shell configuration (that is 1s1) contains only one electron in the s-orbital, it qualifies as an Alkali metal. A noble gas structure, which

1. What is created by the reaction of natural gas and steam in the Haber-Bosch process?a) Ammoniab) Nitrogenc) Oxygend) Hydrogen Answer: dExplanation: The steam reformation of methane is the reaction of natural gas and steam. It is a critical stage in the Bosch-Haber (industrial ammonia production process), which creates hydrogen gas, H2, as one of the two reactants alongside nitrogen in the production of ammonia in the presence of an iron catalyst. 2. What form does nitrogen take in plants?a) Ammoniab) Amidec) Nitrated) Nitrite Answer: cExplanation: Plants mostly absorb nitrogen in the form of nitrate ions, as well as ammonium

1. Which of the following is not a suitable ore for extracting iron?a) Hematiteb) Magnetitec) Siderited) Iron Pyrites Answer: dExplanation: FeS2 is the chemical formula for iron pyrite. Because iron pyrite is exothermic and poses a safety risk in mines, it is more cost-effective to extract iron from other ores like magnetite and hematite. Pyrites are generally unstable, and they have the potential to transform into sulphurous minerals. 2. Which of the following ore is used to extract silver?a) Calamineb) Cinnabarc) Argentited) Malachite Answer: cExplanation: Argentite, commonly known as a silver glance, is the only silver ore with the chemical composition

1. When the molecules of a substance are kept at the surface of a solid or a liquid, what is the name of the process? a) Absorption b) Adsorption c) Sorption d) Desorption Answer: b Explanation: Adsorption is the process of a substance’s molecules accumulating in a larger concentration on the surface of a solid or a liquid. Gases, for example, adsorb on the surface of the charcoal. 2. Which of the following assertions about the extent of physisorption is correct? a) Increases with increase in temperature b) Decreases with increase in surface area c) Decreases with increase in the strength

1. The study of reaction kinetics is called __________.a) Rate of reactionb) Mechanism of reactionc) Factors which affect the rate of reactiond) All of the mentioned Answer: dExplanation: Reaction kinetics is the study of reaction rates, mechanisms, and the factors that influence reaction rates. 2. The reaction rate constant can be defined as the rate of reaction when each reactant’s concentration is ___________.a) Zerob) Unityc) Doubled the initial concentrationd) Infinite Answer: bExplanation: The reaction rate constant can be defined as the rate of the reaction when all of the reactants’ concentrations are unity. The rate of a chemical reaction is quantified by

1. A cathode and an anode are the most common components of an electrochemical cell. Which of the following claims about the cathode is correct?a) Oxidation occurs at the cathodeb) Electrons move into the cathodec) Usually denoted by a negative signd) Is usually made up of insulating material Answer: bExplanation: Metal electrodes are commonly used as cathodes. It is on this electrode that reduction occurs. In a galvanic cell, the cathode is the positive electrode, while in an electrolytic cell, it is the negative electrode. The cathode attracts electrons. 2. Which of the following claims about electrochemical cells is true?a) Cell potential

1. The volume occupied by a single gas in a mixture at the same temperature and pressure is referred to as the single-gas volume.a) Absolute volumeb) Partial volumec) Total volume of a gas mixtured) None of the mentioned Answer: bExplanation: At the same temperature and pressure, the volume occupied by a single gas alone in a combination is a portion of a volume. 2. The pressure that a single component in a gaseous mixture would exert if it existed alone in the same volume as the mixture and at the same temperature as the mixture is referred to as.a) Absolute pressureb) Partial

1. What are the key factors of solid-state reactions?a) Size of the particlesb) Mechanical properties of solidsc) Thermodynamic and kinetic factorsd) Environmental factors Answer: dExplanation: Thermodynamic considerations decide whether or not a reaction should occur in the solid-state by assessing the change in free energy involved, while kinetic factors govern the rate at which the reaction happens. 2. Which approach can be employed to produce a high degree of homogeneity in the creation of ZnFe2O4 spinel?a) Distillation methodb) Vaporization methodc) Coprecipitation methodd) Crystallization method Answer: cExplanation: The reactants are mixed together manually or mechanically in a conventional solid-state reaction, and the ensuing