Description : A photochemical reaction is __________ light. (A) Initiated by (B) Accompanied with emission of (C) Catalysed by (D) Used to convert heat energy into
Last Answer : (A) Initiated by
Description : Pick out the correct statement. (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state (C) A photochemical reaction is catalysed by ... occurs when the energy of the reacting molecule is less than the activation energy of the reaction
Last Answer : (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state
Description : β-rays emission in radioactive disintegration is always accompanied by the emission of (A) γ-rays (B) α-rays (C) Neutrons (D) None of these
Last Answer : (A) γ-rays
Description : The emission of a positron from a radioactive atom is generally accompanied by the emission of one of the following. Is it accompanied by the emission of: w) a meson x) a baryon y) an antineutrino z) a neutrino
Last Answer : ANSWER: Z -- A NEUTRINO
Description : Pick out the wrong statement. (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C ... in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & prod
Last Answer : (C) Enzymes help in increasing the activation energy of the reaction
Description : Photochemical reaction rate does not depend significantly on temperature, because (A) It is a reversible reaction (B) It is an exothermic reaction (C) The energy of reacting molecules exceeds the activation energy by absorption of light (D) None of these
Last Answer : (C) The energy of reacting molecules exceeds the activation energy by absorption of light
Description : Photochemical smog is formed from automobile exhaust (A) By reaction of hydrocarbon & nitric oxide in presence of sunlight (B) Appears only on sunny days (C) Is harmful for crops and trees also besides causing eye irritation & asthma (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : What is the Thiele modulus of the solid catalysed first order reaction as shown in the bellow figure, if the pore diffusion offers negligible resistance to reaction? (A) < 5 (B) < 0.5 (C) > 1 (D) 5
Last Answer : (B) < 0.5
Description : For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the __________ adsorption. (A) Physical (B) Chemical (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (B) Chemical
Description : For high conversion in a highly exothermic solid catalysed reaction, use a __________ bed reactor. (A) Fixed (B) Fluidised bed reactor followed by a fixed (C) Fixed bed reactor followed by a fluidised (D) Fluidised
Last Answer : (B) Fluidised bed reactor followed by a fixed
Description : In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for (A) Fast reactions in catalyst of small pore diameter (B) Fast reaction in catalyst ... reactions in catalyst of small pore diameter (D) Slow reactions in catalyst of large pore diameter
Last Answer : (C) Slow reactions in catalyst of small pore diameter
Description : If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst (A) Porosity is very important (B) Porosity is of less importance (C) Internal surface area is utilised efficiently (D) None of these
Last Answer : (B) Porosity is of less importance
Description : . A reaction which is catalysed by an acid is also catalysed by any substance, which has a tendency to (A) Lose a proton (B) Gain a proton (D) None of these (C) Lose an electron
Last Answer : (A) Lose a proton
Description : Kinetics of a solid catalysed reaction can best be studied in a __________ reactor. (A) Batch (B) Plug-flow (C) Mixed (D) None of these
Last Answer : (C) Mixed
Description : A rise in temperature (A) Normally tends to increase the reaction rate (B) Does not affect a catalysed reaction (C) Does not affect photo-chemical reaction rates (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : A reaction which is catalysed by a base is catalysed by all substances which have a tendency to (A) Lose a proton (B) Gain a proton (C) Gain an electron (D) None of these
Last Answer : (B) Gain a proton
Description : A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and kg respectively. The effective rate constant (ke ff) is given by (A) ke ff = k + kg ( ... + kg )/2 (C) ke ff = (kkg ) 1/2 (D) 1/ke ff = 1/k + 1/kg
Last Answer : (D) 1/ke ff = 1/k + 1/kg
Description : The effectiveness factor for large value of Thiele modulus [L√(K/D1 )] of a solid catalysed first order reaction is equal to (where, L = length of the reactor, cm, D1 = diffusion co-efficient, cm2 /second). (A) L √(K/D1 ) (B) 1/[L√(K/D1 )] (C) 1 (D) ∞
Last Answer : (B) 1/[L√(K/D1 )]
Description : Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known as (A) Photochemical smog (B) Peroxyacetyl nitrate (PAN) or methyl nitrite (C) Benzopyrene (D) Polyacrylonitrile
Last Answer : (B) Peroxyacetyl nitrate (PAN) or methyl nitrite
Description : Safe limit' called Threshold Limit Value (TLV) of carbon monoxide in atmospheric air is < 50 ppm. The main source of carbon monoxide pollutant in air is the (A) Industrial chimney exhaust (B) Automobiles exhaust (C) Photochemical reaction in polluted atmosphere (D) Burning of domestic fuel
Last Answer : (B) Automobiles exhaust
Description : Which of the following is an autocatalytic reaction? (A) Photochemical reactions (B) Microbial fermentation reactio (C) Enzyme fermentation reaction (D) Ammonia synthesis reaction
Last Answer : (B) Microbial fermentation reaction
Description : A reaction in which one of the products of reaction acts as a catalyst is called a/an __________ reaction. (A) Catalytic (B) Autocatalytic (C) Photochemical
Last Answer : (C) Photochemical
Description : The rate of reaction of a/an __________ reaction is not affected by temperature rise. (A) Autocatalytic (B) Photochemical (C) Consecutive (D) Zero order
Last Answer : (B) Photochemical
Description : The reaction between oxygen and organic material is a/an __________ reaction. (A) Exothermic (B) Endothermic (C) Biochemical (D) Photochemical
Last Answer : (A) Exothermic
Description : The reaction in which one of the products of reaction acts as a catalyst is called a/an __________ reaction. (A) Biochemical (B) Photochemical (C) Catalytic (D) Autocatalytic
Last Answer : (D) Autocatalytic
Description : Exposure of a photographic plate to produce a latent image is an example of __________ reaction. (A) Very slow (B) Very fast (C) Photochemical (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Pick out the wrong statement. (A) Visible radiation provides the necessary activation energy in photochemical reactions (B) The order and molecularity of a complex reaction may not be the same (C) For ... rate constant (k) (D) Molecularity of the reaction is always a whole number greater than zero
Last Answer : (B) The order and molecularity of a complex reaction may not be the same
Description : Plants produce carbohydrates from the CO2 present in the atmosphere by (A) Polymerisation (B) Photochemical reaction (C) Oxidation (D) None of these
Last Answer : (B) Photochemical reaction
Description : Absorption accompanied with chemical reaction is exemplified by the absorption of (A) Ammonia in water (B) Benzol present in coke oven gas by wash oil (C) SO2 in alkaline solution (D) All (A), (B) and (C)
Last Answer : (C) SO2 in alkaline solution
Description : Component A is diffusing in a medium B. The flux NA relative to a stationary point is equal to the flux due to molecular diffusion, if (A) Mass transfer is accompanied by reaction (B ... stagnant medium B (C) Molecular mean free path is high (D) There is equimolar counter diffusion
Last Answer : (D) There is equimolar counter diffusion
Description : Pick out the correct statement. (A) A chemical reaction accompanied by absorption of heat is called an exothermic reaction (B) A chemical reaction accompanied by evolution of heat is called an ... does not change on changing the concentration units (D) Chemical equilibrium state is dynamic in nature
Last Answer : (C) The rate constant for a first order reaction does not change on changing the concentration units
Description : Particulate' air pollutants are finely divided solids and liquids. Which of the following is not a ‘particulate’? (A) Dust & mists (B) Smoke & fumes (C) Photochemical smog & soot (D) None of these
Last Answer : (D) None of these
Description : Which of the following is not a secondary air pollutant? (A) Ozone (B) Photochemical smog (C) Sulphur dioxide (D) All (A), (B) & (C)
Last Answer : (C) Sulphur dioxide
Description : Which of the following emissions in the exhaust gas of an I.C. engine causes the formation of photochemical smog? (A) Nitrogen oxides (B) Hydrocarbons (C) Both 'a' & 'b' (D) Carbon monoxide
Last Answer : (C) Both 'a' & 'b'
Description : An oxidation process is accompanied with decrease in the (A) Number of electrons (B) Oxidation number (C) Number of ions (D) All (A), (B) & (C)
Last Answer : (A) Number of electrons
Description : Many living organisms exhibit the unique property of producing visible light. The compound that is oxidized with subsequent light emission is usually referred to as luciferin. What is the enzyme which catalyzes the reaction known as?
Last Answer : ANSWER: Luciferase
Description : All the following statements about charging of tRNA are correct except (A) It is catalysed by amino acyl tRNA synthetase (B) ATP is converted into ADP and Pi in this reaction (C) The enzyme recognizes the tRNA and the amino acid (D) There is a separate enzyme for each tRNA
Last Answer : Answer : B
Description : The first reaction unique to purine nucleotide synthesis is catalysed by (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Phosphoribosyl glycinamide synthetase (D) Formyl transferase
Description : The α-amino group of the new amino acyl tRNA in the A site carries out a nucleophilic attack on the esterified carboxyl group of the peptidyl tRNA occupying the P site. This reaction is catalysed by (A) DNA polymerase (B) RNA polymerase (C) Peptidyl transferase (D) DNA ligase
Last Answer : Answer : C
Description : The decarboxylation reaction in HMP shunt is catalysed by (A) Gluconolactone hydrolase (B) 6-Phosphogluconate dehydrogenase (C) 6-Phosphogluconate decarboxylase (D) Transaldolase
Description : An allosteric enzyme is generally inhibited by (A) Initial substrate of the pathway (B) Substrate analogues (C) Product of the reaction catalysed by allosteric enzyme (D) Product of the pathway
Last Answer : Answer : D
Description : Galactose 1-phosphate is converted to uridine diphosphate galactose, the reaction is catalysed by the enzyme: (A) Glactokinase (B) Galactose 1-phosphate uridyl transferase (C) Uridine diphospho galactose 4-epimerase (D) UDP glucose pyrophosphorylase
Description : UDP glucose is converted to UDP glucurronate, a reaction catalysed by UDP glucose dehydrogenase requires (A) NAD+ (B) FAD (C) NADP (D) FMN
Last Answer : Answer : A
Description : Glucose 6-phosphate is converted to glucose 1-phosphate in a reaction catalysed by the enzyme phosphoglucomutase, which is (A) Phosphorylated (B) Dephosphorylated (C) Phosphorylated-dephosphorylated (D) Phosphorylated-dephosphorylatedrephosphorylated
Description : The reaction catalysed by α-ketoglutarate dehydrogenase in the citric acid cycle requires (A) NAD (B) NADP (C) ADP (D) ATP
Description : Riboflavin is a coenzyme in the reaction catalysed by the enzyme (A) Acyl CoA synthetase (B) Acyl CoA dehydrogenase (C) β-Hydroxy acyl CoA (D) Enoyl CoA dehydrogenase
Description : The reaction catalysed by phosphofructokinase (A) Is activated by high concentrations of ATP and citrate (B) Uses fruitose-1-phosphate as substrate (C) Is the rate-limiting reaction of the glycolytic pathway (D) Is inhibited by fructose 2, 6-bisphosphate
Last Answer : C
Description : Conversion of glucose to glucose-6-phosphate, the first irreversible reaction of glycolysis, is catalysed by (a) phosphofructokinase (b) aldolase (c) hexokinase (d) enolase.
Last Answer : (c) hexokinase
Description : The product(s) of reaction catalysed by nitrogenase in root nodules of leguminous plants is/are (a) ammonia alone (b) nitrate alone (c) ammonia and oxygen (d) ammonia and hydrogen.
Last Answer : (d) ammonia and hydrogen.