Description : Which of the following assumptions of Freunlich adsorption isotherm is incorrect? (a) The constants are temperature dependent (b) It is valid over a range of pressure only (c) Adsorption ... equation is purely an empirical equation (d) The adsorbed molecules may be multimolecular in thickness
Last Answer : (d) The adsorbed molecules may be multimolecular in thickness
Description : Pick out the wrong statement. Generally for physical adsorption, a gas of (A) Higher molecular weight is adsorbed in preference to a gas of low molecular weight (B) High critical temperature ... volatility is adsorbed in preference to a gas of high volatility (D) None of these
Last Answer : (D) None of these
Description : The rate expression for a heterogeneous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + KR.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR ... R and A) (A) E (B) E + ΔHA (C) E + ΔHA - ΔHR ) (D) ΔHA + ΔHR
Last Answer : (C) E + ΔHA - ΔHR )
Description : In Langmuir treatment of adsorption, (A) Whole surface of the catalyst does not have the same activity for adsorption and there is attraction between the adsorbed molecule (B) Whole surface of ... same mechanism (D) Extent of adsorption is more than one complete monomolecular layer on the surface
Last Answer : (B) Whole surface of the catalyst is essentially uniform and the adsorbed molecule has no effect on the rate of adsorption per site
Description : Brunauer, Emmet and Teller (BET) equation is used to determine the specific surface area of a porous particle but not the pore volume & the porosity of the catalyst bed. Which of the following postulates ... (except the first one) is involved in each of the evaporation process (D) None of these
Last Answer : (B) There is no dynamic equilibrium between successive layer
Description : An adsorption isotherm equation proposed by Langmuir is of the form `V = (V_(0)bPO)/((1 + bP))` where V is the volume of gas adsorbed at pressure P. F
Last Answer : An adsorption isotherm equation proposed by Langmuir is of the form `V = (V_(0)bPO)/((1 + bP))` where V is ... of V on P can be depicted as B. C. D.
Description : Adsorption of a gas follows Freundlich adsorption isotherm. In the given plot, x is the mass of the gas adsorbed on mass m of the adsorbent at pressur
Last Answer : Adsorption of a gas follows Freundlich adsorption isotherm. In the given plot, x is the mass of the gas adsorbed on mass m ... p^(1//2)` D. `p^(1//4)`
Description : The change in enthalpy per unit weight of adsorbed gas when adsorbed on gas free or "outgassed" adsorbent to from a definite concentration of adsorbate is called its (A) Integral heat of adsorption (B) Heat of wetting (C) Differential heat of adsorption (D) Heat of normal condensation
Last Answer : (A) Integral heat of adsorption
Description : The change in enthalpy, when a unit quantity of gas is absorbed by relatively large quantity of adsorbent (on which a definite concentration of the adsorbed gas already exists) is termed as the (A) ... (B) Heat of wetting (C) Integral heat of adsorption (D) None of these
Last Answer : (A) Differential heat of adsorption
Description : Which of the following is incorrect about heterogeneous catalysis? a. The most effective catalysts are those which have small surface area b. Seperation of catlyst is easy c. Increase in the rate of reaction is due to decrease in the activation energy d. It is based upon the phenomenon of adsorption
Last Answer : a. The most effective catalysts are those which have small surface area
Description : Assertion :- The graphical representation of physical adsorption with temp is Reason :- This is weak adsorption & adsorption is exothermic process.
Last Answer : Assertion :- The graphical representation of physical adsorption with temp is Reason :- This is weak ... D. If both Assertion & Reason are False.
Description : Assertion (A): Micelles are formed by surfactant molecules above the critical micellization concentration `(CMC)` . Reason(R): The conductivity of a s
Last Answer : Assertion (A): Micelles are formed by surfactant molecules above the critical micellization concentration ` ... If both Assertion & Reason are False.
Description : Assertion :- A sol of `As_(2)S_(3)` prepared by the action of `H_(2)S` on `As_(2)O_(3)` is negatively charge. Reason :- Due to adsorption of `S^(-2)`
Last Answer : Assertion :- A sol of `As_(2)S_(3)` prepared by the action of `H_(2)S` on `As_(2)O_(3) ... Reason is False. D. If both Assertion & Reason are False.
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 : In case of physical adsorption, the difference between heat of adsorption and heat of normal condensation is (A) Equal to the heat of formation of surface compound (B) Equal to the heat of wetting (C) Zero (D) Called integral heat of adsorption
Last Answer : (B) Equal to the heat of wetting
Description : The mass of argon adsorbed per unit mass of carbon surface is plotted against pressure. Which of the following plots is correct if x and m represent t
Last Answer : The mass of argon adsorbed per unit mass of carbon surface is plotted against pressure. Which of the ... Represents extrapolated data) A. B. C. D.
Description : When `O_(2)` is adsorbed on a metallic surface, electron transfer electron transfer occurs from the metal to `O_(2).` The TRUE statement (s) regarding
Last Answer : When `O_(2)` is adsorbed on a metallic surface, electron transfer electron transfer occurs from the metal ... D. bong length of `O_(2)` is increased
Description : Which will be adsorbed more readily on the surface of charcoal and why NH3 or CO2?
Last Answer : Ans: The critical temperature NH3 is more CO2, therefore NH3 is liquefied more easily than CO2. Hence NH3 has higher intermolecular forces of attraction and hence it adsorbed more readily.
Description : Burning of Gasoline initially requires heat before it burns spontaneously. Which of the following does not give a good explanation of this phenomenon? a. the initial heat rises the enthalpy of the reactant ... of products. d. The enthalpy of the product is lower than the enthalpy of the reactant
Last Answer : the enthalpy of reactants is lower than the enthalpy of products.
Description : The difference between Threshold energy and average energy of the molecules is called activation energy. Ina chemical reaction lowers the rate of reaction the greater will be. The activation energy
Last Answer : How do you define the molecularity of a reaction ?
Description : Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules
Last Answer : (B) Thermal energy of the molecules
Description : A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction
Last Answer : (C) Is capable of reacting with any one of the reactants
Description : The increase in the rate of reaction with temperature is due to (A) Increase in the number of effective collisions (B) Decrease in activation energy (C) Increase in the average kinetic energy of the reacting molecules (D) None of these
Last Answer : (B) Decrease in activation energy
Description : Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of ... molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction
Last Answer : (C) A catalyst lowers the activation energy of the reacting molecules
Description : The energy of activation of a chemical reaction: (A) Is same as heat of reaction at constant pressure (B) Is the minimum energy which the molecules must have before the reaction can take place (C) Varies as fifth power of the temperature (D) Both (B) and (C)
Last Answer : (B) Is the minimum energy which the molecules must have before the reaction can take place
Description : The reaction rate almost gets doubled for 10°C rise in temperature. This is due to the fact that the (A) Increased temperature reduces the activation energy (B) Fraction of molecules having threshold energy increases (C) Collision frequency increases (D) Value of threshold energy decreases
Last Answer : (B) Fraction of molecules having threshold energy increases
Description : A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than
Last Answer : (D) Equal to or more than
Description : A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than
Description : Assertion : Phenol has lower boiling point then water Reason : Water forms more number of hydrogen bonds
Last Answer : Assertion : Phenol has lower boiling point then water Reason : Water forms more number of hydrogen ... false D. Assertion is false, Reason is true
Description : Assertion: The O - O bond lengths in ozone molecule are intermediate between single and double bonds. Reason: `O_(3)` molecule is a resonance hybrid.
Last Answer : Assertion: The O - O bond lengths in ozone molecule are intermediate between single and double bonds. ... I is not correct and Statement-II is correct
Description : Assertion `:-` Mostly aquatic animals are ammonotelic. Reason `:-` Ammonia is the most toxic form and requires large amount of water for its eliminati
Last Answer : Assertion `:-` Mostly aquatic animals are ammonotelic. Reason `:-` Ammonia is the most toxic form and ... . D. If both Assertion & Reason are false.
Description : Assertion : During embrynic stage testes descend down and at the time of birth , it comes into scrotum . Reason : Spermatogenesis process requires les
Last Answer : Assertion : During embrynic stage testes descend down and at the time of birth , it comes into scrotum ... . D. If both Assertion & Reason are False.
Description : Assertion (A): In anti-friction bearings, the frictional resistance is very low as the shaft held by it remains in floating condition by the hydrodynamic pressure developed by the lubricant. [IES-2006] Reason (R): In hydrodynamic ... of A (c) A is true but R is false (d) A is false but R is true
Last Answer : (d) A is false but R is true
Description : Assertion (A) : Periplaneta americana is nocturnal, omnivorous, household pest. Reason (R) : It is because it acts as scavenger. (a) A is true but R is false. (b) A is false but R is true. (c) Both ... R is correct explanation of A. (d) Both A and R are true but R is not correct explanation of A
Last Answer : (d) Both A and R are true but R is not correct explanation of A.
Description : Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]. Assertion: Fast decoupled load flow method gives approximate load flow solution because it uses several assumptions. Reason: Accuracy ... the correct reason for [a]. c) [a] is false and [r] is true.
Last Answer : c) [a] is false and [r] is true
Description : Read the following statements - one labelled as Assertion (A) and the other as Reason (R) : Assertion (A) : Qualitative research in India has a long way to go to reach international standards. Reason (R) : Because the funding ... (C) (A) is true, but (R) is false. (D) Both (A) and (R) are false.
Last Answer : (C) (A) is true, but (R) is false.
Description : Assertion (A): The coin when flipped next time will come up tails. Reason (R): Because the coin was flipped five times in a row, and each time it came up heads. Choose the correct answer from below: (A) Both (A ... A). (D) (A) is doubtful, (R) is false, and (R) is the correct explanation of (A).
Last Answer : (C) (A) is doubtful, (R) is true, and (R) is not the correct explanation of (A).
Description : Assertion (A) : Mass media promote a culture of violence in the society. Reason (R) : Because violence sells in the market as people themselves are violent in character. (A) Both (A) and (R) are true and (R) is the correct ... ). (C) (A) is true, but (R) is false. (D) Both (A) and (R) are false.
Last Answer : (D) Both (A) and (R) are false.
Description : The sorting out of molecules according to size and shape may be adapted to protein purification in this technique: (A) Adsorption chromatography (B) Gel filtration chromatography (C) Paper chromatography (D) None of these
Last Answer : Answer : B
Description : Assertion :-`CO_(2)` molecules is non-polar while `SO_(2)` Reason : - Carbon atom is smaller than sulphur.
Last Answer : Assertion :-`CO_(2)` molecules is non-polar while `SO_(2)` Reason : - Carbon atom is smaller ... is False. D. If both Assertion & Reason are false
Description : Assertion: The enthalpy of formation of gaseous oxygen molecules at `298K` and under1 atm is zero. Reason: The entropy of formation of gaseous oxygen
Last Answer : Assertion: The enthalpy of formation of gaseous oxygen molecules at `298K` and under1 atm is zero. ... D. If both Assertion & Reason are false.
Description : Assertion :- Zeolite is shape selective catalyst. Reason :- Size of the pores of the catalyst are such that they can trap only selective molecules.
Last Answer : Assertion :- Zeolite is shape selective catalyst. Reason :- Size of the pores of the catalyst are such ... . D. If both Assertion & Reason are False.
Description : Assertion (A) A body can have energy without momentum. Reason (R) Internal energy is present in a body.
Last Answer : Ans:(a)
Description : Diamond is hard because (a) It has strong covalent bonds (b) Discrete molecules of carbon are held by strong Vander Waal’s forces (c) It involves Van der Waal's forces (d) Covalent bonds are directional unlike ionic bonds
Description : For the activation of long chain fatty acids the enzyme thiokinase requires the cofactor: (A) Mg++ (B) Ca++ (C) Mn++ (D) K+
Description : Activation of fatty acids requires all the following except (A) ATP (B) Coenzyme A (C) Thiokinase (D) Carnitine
Last Answer : Answer : D
Description : Leukocyte activation and adhesion to vascular endothelial cells is a critical step in the inflammatory process. This process is regulated by which of the following molecules? a. The selectins b. The b5 integrins c. The immunoglobulin supergene family d. Nitric oxide e. IL-8
Last Answer : Answer: a, c, d, e The temporal events that initiate and propagate neutrophil recruitment and inflammation include endothelial cell activation and expression of endothelial-derived ... role in neutrophil recruitment and activation, and the continued propagation of the inflammatory response
Description : The mechanism by which neostigmine improves contraction of myasthenic muscle involves: A. Repetitive binding of the acetylcholine molecules to the same receptors at the muscle endplate B. Diffusion of ... Activation of motor end-plate receptors by neostigmine molecules themselves D. All of the above
Last Answer : D. All of the above
Description : When adding electric energy to water molecules can it cause the bonds between Hydrogen and oxygen to break?
Last Answer : What is the answer ?