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 : The Graetz number is concerned with the (A) Mass transfer between a gas and a liquid (B) Absorption with chemical reaction (C) Heat transfer in turbulent flow (D) Heat transfer in laminar flow
Last Answer : (D) Heat transfer in laminar flow
Description : Which of the following unit operations makes use of Thiele-Geddes equation? (A) Liquid-liquid extraction (B) Solid-liquid extraction (C) Multi-component absorption with chemical reaction (D) Multi-component distillation
Last Answer : (D) Multi-component distillation
Description : Absorption with chemical reaction' is involved in the removal of (A) Carbon dioxide from gaseous stream using alkaline solution (B) Benzol from coke oven gas using solar oil/wash oil (C) Ammonia ... gas using refrigerated water (D) Tar from coke oven gas in primary gas coolers using chilled water
Last Answer : (A) Carbon dioxide from gaseous stream using alkaline solution
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 : An alkaline solution is used to reduce the concentration of carbon dioxide in a stream from 10% to 0.1% by absorption with irreversible chemical reaction. The overall number of transfer units based on gas phase is: (A) 9.21 (B) 4.605 (C) 100 (D) 0.001
Last Answer : (B) 4.605
Description : Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is ... reflux in case of distillation operation requires infinite number of plates for a binary system separation
Last Answer : (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion
Description : The Hatta number is important in (A) Multi-component distillation (B) Binary distillation (C) Gas absorption without chemical reaction (D) Gas absorption with chemical reaction
Last Answer : (D) Gas absorption with chemical reaction
Description : Pick out the wrong statement (A) Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure substance (B) In case of gas absorption, HETP is ... reaction (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Last Answer : (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Description : In the blast furncae the reaction that occurs in the zone of heat absorption is
Last Answer : In the blast furncae the reaction that occurs in the zone of heat absorption is A. `CO_(2)+C to 2CO` B. ` ... CO_(2)` D. `FeO+SiO_(2) to FeSiO_(3)`
Description : A chemical reaction in which heat is liberated is called
Last Answer : exothermic reaction.
Description : What is chemical reaction that gives off heat called?
Last Answer : Exothermic reactions give off heat.
Description : Pick up the incorrect statement from the following: (A) The degree of grinding of cement, is called fineness (B) The process of changing cement paste into hard mass, is known as setting of ... (D) The heat generated during chemical reaction of cement with water, is known as heat of hydration
Last Answer : Answer: Option C
Description : The browning reaction due to chemical reaction between an amino acid and a reducing sugar, usually requiring heat is called as _____: a. Dextrinization b. Maillard reaction c. Scorching d. Caramelization
Last Answer : b. Maillard reaction
Description : Heat transfer horizontally within the atmosphere is called – (1) Conduction (2) Convection (3) Absorption (4) Advection
Last Answer : (4) Advection Explanation: Convection transfers heat vertically into the atmosphere. In order for heat to be transferred to other regions, it must be transferred horizontally by the wind. The horizontal ... advection is the transport of pollutants or silt in a river by bulk water flow downstream.
Description : Heat transfer horizontally within the atmosphere is called (1) Conduction (2) Convection (3) Absorption (4) Advection
Last Answer : Advection
Description : Name the chemical element that is eleventh in the Lanthanide Series in the periodic table. Because of the metal's high thermal-neutron-absorption cross section, it has been of much interest in terms of use in nuclear reactor hardware. The chemical symbol for this element is Er.
Last Answer : ANSWER: ERBIUM
Description : In PS I the reaction centre chlorophyll a has an absorption peak at 700 nm, hence is called (A)____ while in PS II it has absorption maxima at 680 nm
Last Answer : In PS I the reaction centre chlorophyll a has an absorption peak at 700 nm, hence is called (A) ... absorption maxima at 680 nm and is called (B)____
Description : Chemical reaction in which heat is evolved?
Last Answer : Exothermic reaction
Description : Chemical reaction in which heat is ab- sorbed?
Last Answer : Endothermic reaction
Description : Chemical reaction in which heat is re- leased?
Description : The atmosphere near the earth's surface is heated from below. Which of the following does not significantly contribute to this heating -----------? A. Conduction of heat upward from a ... infrared energy that has been radiated from the surface D. Heat energy from the earth's interior (Answer)
Last Answer : D. Heat energy from the earth’s interior (Answer)
Description : What is a chemical reaction that releases energy by light or heat?
Last Answer : Need answer
Description : What is the best term to describe a chemical reaction that absorbs heat energy?
Last Answer : What is the answer ?
Description : An enzyme promotes a chemical reaction by (A) Lowering the energy of activation (B) Causing the release of heat which acts as a primer (C) Increasing molecular motion (D) Changing the free energy difference between substrate and product
Last Answer : Answer : A
Description : Analogy between mass and heat transfer is not applicable in case of (A) Same velocity profile or equal eddy diffusivities (B) Thermal or pressure mass diffusion (C) Viscous heating or chemical reaction (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : The role of a catalyst in a chemical reaction is to change the (A) Equilibrium constant (B) Activation energy (C) Final products (D) Heat of reaction
Last Answer : (B) Activation energy
Description : Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the (A) Activation energy (B) Equilibrium constant (C) Heat of reaction (D) None of these
Last Answer : (A) Activation energy
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 catalyst in a first order chemical reaction changes the (A) Equilibrium constant (B) Activation energy (C) Heat of formation of the product (D) Heat of reaction
Description : If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will (A) Increase (B) Decrease (C) Remain unaltered (D) Increase or decrease; depends on the particular reaction
Last Answer : (C) Remain unaltered
Description : When an isolated thermodynamic system executes a process, (A) Work is done (B) Heat transfer takes place (C) Mass flow occurs across the boundary of the system (D) No chemical reaction takes place within the system
Last Answer : D) No chemical reaction takes place within the system
Description : Which of the following events is heat exchange involved? a. when there is a phase change b. when there is a chemical reaction c. when the gas expands adiabatically d. when there is difference in temperature
Last Answer : when the gas expands adiabatically
Description : What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential ... decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.
Last Answer : A The reaction follows an alternative pathway of lower activation energy.
Last Answer : : The heat absorption capacity of an object depends on the color.
Last Answer : " Black" material has high heat absorption capacity.
Description : The evolution of heat of solution takes place in ammonia absorption plant when (a) ammonia vapour goes into solution (b) ammonia vapour is driven out of solution (c) lithium bromide mixes with ammonia (d) weak solution mixes with strong solution
Last Answer : Ans: a
Description : Choose the wrong statement (a) Temperature of medium being cooled must be below that of the evaporator (b) Refrigerant leaves the condenser as liquid (c) All solar thermally operated absorption systems are capable only of intermittent operation (d) frost on evaporator reduces heat transfer
Description : Pick up the correct statement about giving up of heat from one medium to other in ammonia absorption system (a) strong solution to weak solution (b) weak solution to strong solution (c) strong solution to ammonia vapour (d) ammonia vapour to strong solution.
Last Answer : Ans: b
Description : Which of the following is most important for absorption of heat radiated from the Sun as well as from the Earth? (1) Carbon dioxide (2) Oxygen (3) Carbon monoxide (4) Nitrogen
Last Answer : (1) Carbon dioxide Explanation: Carbon dioxide is a green house gas that absorbs heat radiated from the Sun as well as re-radiated heat from the Earth's surface.
Description : Heat is generated in a nuclear reactor (thermal) by (A) Combustion of a nuclear fuel e.g. uranium (B) Fusion of atoms of uranium (C) Absorption of neutrons in uranium atoms (D) Fission of U-235 by neutrons
Last Answer : (D) Fission of U-235 by neutrons
Description : Physical absorption is (A) An irreversible phenomenon (B) A reversible phenomenon (C) Accompanied by evolution of heat (D) Both (B) and (C)
Description : Low viscosity absorbent is preferred for reasons of (A) Rapid absorption rates and good heat transfer characteristics (B) Improved flooding characteristics (C) Low pressure drop on pumping (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption
Last Answer : (A) Liquid extraction
Description : Absorption accompanied by heat evolution results in (A) Increased capacity of the absorber (B) Increase in equilibrium solubility (C) Decrease in equilibrium solubility (D) None of these
Last Answer : (C) Decrease in equilibrium solubility
Description : Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in (A) Decreased solute solubility (B) Large minimum liquid to gas (L/G) ratio (C) Large number of trays (D) All (A), (B) and (C)
Description : Choose the best definition of dielectric loss. a) Absorption of electric energy by dielectric in an AC field b) Dissipation of electric energy by dielectric in a static field c) Dissipation of heat by dielectric d) Product of loss tangent and relative permittivity
Last Answer : a) Absorption of electric energy by dielectric in an AC field
Description : Pick out the wrong statement. (A) A refrigeration cycle violates the second law of thermodynamics (B) Refrigeration cycle is normally represented by a temperature vs. entropy plot (C) In a refrigerator, ... (D) One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW
Last Answer : (A) A refrigeration cycle violates the second law of thermodynamics
Description : Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of (A) Sublimation (B) Fusion (C) Transition (D) Vaporisation
Last Answer : C) Transition
Description : Cooling tower is a ______device a) Heat absorption b) heat rejection c) Both a and b c) neither a nor b
Last Answer : heat rejection