Description : Which of the following statement(s) is (are) true for the given situation? Exposure of silver chloride to sunlight for a long duration turns grey due to (i) formation of silver by decomposition of silver chloride (ii) sublimation of ... (b) (ii), (i) and (iii) (c) (ii) and (iii) (d) (iv) only
Last Answer : (a) (i) only
Description : The working of a dry cell is based on - (1) Decomposition reaction (2) Spontaneous oxidation-reduction reaction (3) Combination reaction. (4) Electrolysis
Last Answer : (4) Electrolysis Explanation: A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of ... of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
Description : Bleaching action of chlorine is by - (1) Decomposition (2) hydrolysis (3) reduction (4) oxidation
Last Answer : (4) oxidation Explanation: Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
Description : Sulphur dioxide bleaches colouring matter by – (1) Reduction (2) Dehydration (3) Decomposition (4) Oxidation
Last Answer : (1) Reduction Explanation: Sulphur dioxide gas exhibits bleaching properties in presence of moisture. It dissolves in water liberating nascent hydrogen. Nascent hydrogen removes oxygen atoms from the colouring matter (reduces colouring matter) and it loses its colour.
Description : CuO + H2 = Cu + H2O. This equation is an example of - (1) Oxidation (2) Decomposition (3) Reduction (4) Redox
Last Answer : (4) Redox
Description : Bleaching action of chlorine is by - (1) decomposition (2) hydrolysis (3) reduction (4) oxidation
Description : Which of the following reactions involve NEITHER oxidation nor reduction? w) burning antimony in chlorine x) decomposition of potassium chlorate y) reaction of sodium with water z) reaction of potassium hydroxide with nitric acid
Last Answer : ANSWER: Z -- REACTION OF POTASSIUM HYDROXIDE WITH NITRIC ACID
Description : The working of a dry cell is based on (1) Decomposition reaction (2) Spontaneous oxidation-reduction reaction (3) Combination reaction (4) Electrolysis
Last Answer : Electrolysis
Description : Sulphur dioxide bleaches colouring matter by : (1) Reduction (2) Dehydration (3) Decomposition (4) Oxidation
Last Answer : Reduction
Description : Decomposition of the acetyl salicylic acid at room temperature most likely would occur by (a) Oxidation of the ester (b) Reduction of the carboxylic acid (c) Hydrolysis of the ester
Last Answer : Ans: C
Description : Rusting is the process of – (1) Oxidation (2) Reduction (3) Decomposition (4) Displacement
Last Answer : (1) Oxidation Explanation: Rust is the process of iron (molecules) oxidizing into iron oxide, or rust. General formula of rust is Fe2O3.nH2O
Description : Bleaching action of chlorine is by----? A. Oxidation (Answer) B. Reduction C. Decomposition D. Hydrolysis
Last Answer : A. Oxidation (Answer)
Description : Rusting of Iron involves--------? A. Reduction B. Oxidation (Answer) C. Decomposition D. Displacement
Last Answer : B. Oxidation (Answer)
Description : During decomposition, energy is absorbed in the form of heat, light or electricity for breaking down the reactants which is known as: (a) exothermic reaction (b) endothermic reaction (c) reduction reaction (d) oxidation
Last Answer : (b) endothermic reaction
Description : Which two distinct microbial processes are responsible for the release of fixed nitrogen as dinitrogen gas (N2) to the atmosphere? (a) Aerobic nitrate oxidation and nitrite reduction (b) ... fixation by Rhizobium in root nodules of legumes (d) Anaerobic ammonium oxidation and denitrification
Last Answer : (d) Anaerobic ammonium oxidation and denitrification
Description : Cement setting under water employs a/an __________ process. (A) Hydration (B) Decomposition (C) Oxidation (D) Reduction
Last Answer : (A) Hydration
Description : Conversion of a substance directly from solid to vapour state is known as (a) Vaporisation (b) Sublimation (c) Decomposition (d) Ionisation
Last Answer : Ans:(b)
Description : Iron is prevented from rusting by coating with zinc. This process is called as – (1) Galvanisation (2) Corrosion (3) Sublimation (4) Reduction
Last Answer : (1) Galvanisation Explanation: 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 ... is hot-dip galvanization, in which steel parts are sub-merged in a bath of molten zinc.
Description : Iron is prevented from rusting by coating with zinc. This process is called as (1) Galvanisation (2) Corrosion (3) Sublimation (4) Reduction
Last Answer : Galvanisation
Description : .Identify the physical and chemical changes from the following (i)Burning of magnesium in air (ii)Electrolysis of water (iii)Tarnishing of silver spoon (iv)Sublimation of iodine -Chemistry
Last Answer : (i) Burning of magnesium in air : Chemical change (ii) Tarnishing of silver spoon : Chemical change (iii) Sublimation of iodine : Physical change (iv) Electrolysis of water to form hydrogen and oxygen is also a chemical change.
Description : The thermal decomposition of alkanes in the absence of air is called : (a) Combustion (b) Oxidation (c) Cracking (d) Hydrogenation
Last Answer : Cracking
Description : Consider the following changes: 1. Curdling of milk 2. Sublimation of camphor 3. Drying of paint 4. Oxidation of SO2 to SO3 The chemical changes are: (a) 1, 2 and 4 only (b) 1, 3 and 4 only (c) 1, 2, 3 and 4 (d) 1, 2 and 3 only
Description : Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other ... of A C. A is true but R is false D. A is false but R is true
Last Answer : ANS: A
Description : All decomposition reaction are endothermic but decomposition of vegetable matter into compost is exothermic because (a) It is an oxidation reaction (b) decomposition done by microbes (c) releases heat energy (d) all the above
Last Answer : (d) all the above
Description : The biological decomposition of organic substances in wastes controlled conditions is called (A) Incineration (B) Biological oxidation (C) Composting (D) None of these
Last Answer : (C) Composting
Description : Mineral oils (e.g. petroleum oils) are preferred over fatty oils (e.g. mustard oil, ghee, tallow, palm oil, olive oil etc.) as a lubricant due to its (A) Poor oxidation stability and high gum forming ... at elevated temperature (C) Hydrolysis tendency in presence of water (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Activated Charcoal is used to remove colouring matter from pure substances by – (1) Bleaching (2) Oxidation (3) Adsorption (4) Reduction
Last Answer : (3) Adsorption Explanation: Heating wood to a very high temperature in the absence of air makes charcoal. When it is heated to an even higher temperature, about 930°C, impurities are driven from its ... . It does so by the process of adsorption, or by attracting these molecules to the surface.
Description : The manufacturing of iron from ironore involves the process of - (1) Oxidation (2) Reduction (3) Electrolysis (4) Fractional distillation
Last Answer : (2) Reduction Explanation: Iron is extracted from iron ore in a huge container called a blast furnace. Iron ores such as hematite contain iron oxide. The oxygen must be removed from the iron oxide to leave the iron behind. Reactions in which oxygen is removed are called reduction reactions.
Description : The manufacture of iron from iron ore involves the process of – (1) oxidation (2) reduction (3) fractional distillation (4) electrolysis
Last Answer : (2) reduction Explanation: The manufacture of iron ore involves the process of reduction. Important ores of iron : Haematite, Magnetite.
Description : The reaction between an acid and a base to give a salt and water is known as a - (1) Neutralisation reaction (2) Reduction reaction (3) Oxidation reaction (4) Exothermic reaction
Last Answer : (1) Neutralisation reaction Explanation: The effect of a base is nullified by an acid and vice-versa. Example: Reaction of Sodium hydroxide with hydrochloric acidNaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
Description : Setting of plaster of paris involves – (1) dehydration process (2) hydration to form other hydrates (3) oxidation process (4) reduction process
Last Answer : (2) hydration to form other hydrates Explanation: The setting of plaster of Paris takes place by hydration due to the formation of a solid crystalline hydrate and hardening of Plaster of Paris is ... . A slight expansion takes place in the process and heat is evolved. This process is exothermic.
Description : What is the process by which an atom gains electrons? w) Reduction x) Neutralization y) Electrolysis z) Oxidation
Last Answer : ANSWER: W -- REDUCTION
Description : The action of concentrated sulfuric acid on sugar best described as: w) catalysis x) oxidation y) reduction z) dehydration
Last Answer : ANSWER: Z -- DEHYDRATION
Description : When an aldehyde is heated with Fehling's solution, the aldehyde undergoes one of the following processes. Does it undergo: w) neutralization x) oxidation y) reduction z) esterification
Last Answer : ANSWER: X -- OXIDATION
Description : The manufacturing of iron from ironore involves the process of (1) Oxidation (2) Reduction (3) Electrolysis (4) Fractional distillation
Description : Activated Charcoal is used to remove colouring matter from pure substances by (1) Bleaching (2) Oxidation (3) Adsorption (4) Reduction
Last Answer : Adsorption
Description : The manufacture of iron from iron ore involves the process of (1) oxidation (2) reduction (3) fractional distillation (4) electrolysis
Last Answer : reduction
Description : Which of the following causes the rusting of iron? a. Oxidation b. Reduction c. Chemical reaction with oxygen d. Chemical reaction with CO2 (1) a and b (2) b and c (3) c and d (4) a and c
Last Answer : a and c
Description : Setting of plaster of paris involves (1) dehydration process (2) hydration to form other hydrates (3) oxidation process (4) reduction process
Last Answer : hydration to form other hydrates
Description : The BOD values of water indicate the (1) amount of organic debris (2) amount of oxygen used for biochemical oxidation (3) amount of oxygen used for biochemical reduction (4) amount of ozone used for biochemical oxidation
Last Answer : amount of oxygen used for biochemical oxidation
Description : Which layer of OSI reference model is responsible for decomposition of messages and generation of sequence numbers to ensure correct re-composition from end to end of the network? (A) Physical (B) Data-link (C) Transport (D) Application
Last Answer : (C) Transport
Description : Pick out the wrong statement. (A) Minimum number of degree of freedom of a system is zero (B) Degree of freedom of a system containing a gaseous mixture of helium, carbon ... ) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Last Answer : (D) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Description : Specific/molar Gibbs free energy for a pure substance does not change during (A) Sublimation (B) Vaporisation (C) Melting (D) Either (A), (B) or (C)
Last Answer : (D) Either (A), (B) or (C)
Description : Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of (A) Solution (B) Vaporisation (C) Formation (D) Sublimation
Last Answer : (B) Vaporisation
Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy
Last Answer : (D) Gibbs free energy
Description : _________ does not change during phase transformation processes like sublimation, melting & vaporisation. (A) Entropy (B) Gibbs free energy (C) Internal energy (D) All (A), (B) & (C)
Last Answer : (B) Gibbs free energy
Description : The change of a gas to a liquid is called: w) vaporization x) sublimation y) condensation z) freezing
Last Answer : ANSWER: Y -- CONDENSATION
Description : What is meant by sublimation ? What is subtraction ?
Last Answer : The process by which a substance is heated from a solid to a gaseous state without being turned into a liquid and when it is cooled from a gaseous state to a solid is called a precipitation.
Description : Sodium vapour lamps glow with yellow colour. This is due to - (1) sublimation of sodium to emit yellow colour (2) the emission of excess energy absorbed by sodium atoms, in the yellow region of the ... (3) the low ionisation energy of sodium (4) its ability to absorb all other colours except yellow
Last Answer : (2) the emission of excess energy absorbed by sodium atoms, in the yellow region of the spectrum Explanation: Sodium Vapour Lamps glow with yellow colour due to the emission of excess energy absorbed by sodium atoms, in the yellow region of the spectrum.
Description : The process of dissolving an acid or a base in water is a highly - (1) Exothermic reaction (2) Endothermic reaction (3) Sublimation reaction (4) Redux reaction
Last Answer : (1) Exothermic reaction Explanation: The process of dissolving an acid or a base in water is a highly exothermic one. This is why care must be taken while mixing concentrated nitric acid or sulphuric acid with water.