Description : Electrolytic reduction of alumina to aluminum by the Hall-Heroult process is carried out
Last Answer : Electrolytic reduction of alumina to aluminum by the Hall-Heroult process is carried out A. In ... which forms a melt with higher melting temparature.
Description : The function of adding cryolite in the electrolytic reduction of alumina by Hall-Heroult process is to
Last Answer : The function of adding cryolite in the electrolytic reduction of alumina by Hall-Heroult ... D. increase the electrical canductivity of alumina
Description : (A) Alumina has hgih condutivity (R ) The mixture of alumia and cryolite is used for electrolytic reduction in order to extract aluminium
Last Answer : (A) Alumina has hgih condutivity (R ) The mixture of alumia and cryolite is used for electrolytic reduction ... (A) is incorrect but (R ) is correct
Description : The metallic aluminium is obtained from pure alumina in the presence of fused cryolite by (A) Electrolysis (B) Electrolytic reduction (C) Electrolytic oxidation (D) None of these
Last Answer : (B) Electrolytic reduction
Description : Electrolytic reduction cell used for conversion of calcined Al2O3to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to (A) Achieve very high ... by the generation of heat (C) Electrolytically dissociate alumina (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : Describe electrolytic reduction of alumina.
Last Answer : i) Aluminium is extracted from alumina by electrolysis of mixture of alumina (20%) , Cryolite (60%) & Calcium fluoride (20%). Addition of cryolite& fluorspar not only makes alumina a ... set free at the cathode is removed periodically in the molten condition from bottom of the cell.
Description : Define the following: Electrolyte, conductivity of electrolytes, specific conductance and equivalent conductance.
Last Answer : Electrolyte: A substance which produces ions in solution or in fused state and allows the electric current to pass through it, is known as electrolyte. Conductivity of electrolytes: The power ... equivalent of solute / electrolyte when placed between two sufficiently large electrodes 1 cm apart.
Description : The major role of flourspar, `CaF_(2)` which is added in small amount in the electrolytic reduction of `Al_(2)O_(3)` dissolved on fused cryolite in fu
Last Answer : The major role of flourspar, `CaF_(2)` which is added in small amount in the electrolytic reduction ... the rate of oxidation of carbon at the anode
Description : How is electrolytic conductance measured experimentally?
Last Answer : Electrolyte conductance can be measured by putting anode and cathode on it and measured the external voltage. Then compared the same with some standard known electrolyte solution. Also, specific ... charge discharge method. So by calculating with inbuilt software we can easily get the conductance.
Description : The major role of fluorpar (`CaF_2` ) which added in small quantities in the electrolyte reduction of alumina dissolved in fused cryolite `(N_(3)AlF_(
Last Answer : The major role of fluorpar (`CaF_2` ) which added in small quantities in the electrolyte reduction ... the rate of oxidation of carbon at the anode
Description : The Weber and the Maxwell are units of measure of: w) conductance x) electrical current y) magnetic flux z) relative speed
Last Answer : ANSWER: Y -- MAGNETIC FLUX
Description : The Tesla and the Gauss are units of measure of: w) conductance x) magnetic field strength y) magnetic flux z) electrical current
Last Answer : ANSWER: X -- MAGNETIC FIELD STRENGTH
Description : Statement -I :Cryolite is used in electrolytic extraction of Al from alumuna.Statement -2: It dissilves alumina
Last Answer : Statement -I :Cryolite is used in electrolytic extraction of Al from alumuna. Statement -2: It dissilves alumina
Description : The fundamental scientific principle in the operation of battery is – (1) acid-base interaction (2) dialysis (3) dissociation of electrolytes (4) oxidation-reduction
Last Answer : (3) dissociation of electrolytes Explanation: The electrolyte consists of a solvent (water, an organic liquid, or even a solid) and one or more chemicals that dissociate into ions in the solvent. These ... that contains ions and can be decomposed by electrolysis, e.g., that present in a battery.
Description : The fundamental scientific principle in the operation of battery is (1) acid-base interaction (2) dialysis (3) dissociation of electrolytes (4) oxidation-reduction
Last Answer : dissociation of electrolytes
Description : Benefits of Waste Heat Recovery a. Reduction in pollution b. Reduction in equipment sizes c. Reduction in auxiliary energy consumption d. All of the above
Last Answer : Ans:- d. All of the above
Description : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. Coke powder is spreadded over the molten electro
Last Answer : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. ... of molten aluminium by air D. (a) both (b)
Description : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. The purpose of adding crylite is :
Last Answer : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. ... . to increase melting point of `Al_(2)O_(3)`
Description : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. What is wrong if anode is made of nickel instant
Last Answer : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite ... CO D. Nickel May be affected by high temperature.
Description : The function of fluorspar in the electrolytic reduction of alumnia dissolved in fused cryotile `(Na_(3)AlF_(6))` is:
Last Answer : The function of fluorspar in the electrolytic reduction of alumnia dissolved in fused cryotile `(Na_(3 ... rate of oxidation of carbon at the cathode
Description : Where does reduction occur in an electrolytic cell?
Last Answer : Cathode
Description : Chlorine gas is produced by the electrolysis of brine (NaCl solution with solid NaCl make up) in mercury electrolytic cell. Which of the following is the anodic reaction? (A) Oxidation of Na + ions (B) Oxidation of Cl - ions (C) Reduction of Na + ions (D) Reduction of Cl - ions
Last Answer : (B) Oxidation of Cl - ions
Description : Titanium is produced by __________ of Ti Cl4. (A) Electrolytic reduction (B) Calcium reduction (C) Magnesium reduction (D) Thermal dissociation
Last Answer : (C) Magnesium reduction
Description : Safety fuse wire used in domestic electrical appliances is made of metal of low (1) Resistance (2) Melting point (3) Specific gravity (4) Conductance
Last Answer : (2) Melting point Explanation: The fuse wire is based on the Joules law of heating which says that when the electric current is allowed to pass through a conductor, the conductor heats up and is ... . For this purpose the material used as fuse wire should have high resistance and low melting point.
Description : Which physical quantity is measured in ‘siemens’? (1) Electric potential (2) Electrical conductance (3) Magnetic flux (4) Refractive index
Last Answer : (2) Electrical conductance Explanation: The Siemens is the unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI).
Description : What do you call the electrical conduction in a photosensitive material which is not exposed to radiation? A. Dark conductance B. Pure conductance C. Black out D. Super conductance
Last Answer : A. Dark conductance
Description : Siemens is the unit of---------? A. Electrical Conductance (Answer) B. Magnetic Conductance C. Electrical Capacitance D. Magnetic Capacitance
Last Answer : A. Electrical Conductance (Answer)
Last Answer : Melting point
Description : Although thermodynamically feasible, in practice, Magnesium metal is not used for the reduction of Alumina in the metallurgy of aluminium.Why?
Last Answer : Ans. : Below the temperature(1623 K) correspoinding to the point of intersection of Al 2O3 and MgO curves in Ellingham diagram, Magnesium can reduce Alumina because the ΔfG o value of Al2O3 at ... to Al. But Magnesium is much costier metal than Aluminium and hence the process will be uneconomical.
Description : Scale formation in boiler is controlled by (A) Preheating of feed water (B) Reduction in hardness, silica & alumina in feed water (C) Keeping the pH value of feed water just below 7 (D) Eliminating H2S in feed water
Last Answer : (B) Reduction in hardness, silica & alumina in feed water
Description : The catalyst used in the production of elemental sulphur from H2S (by oxidation-reduction) is (A) Alumina (B) Silica gel (C) Platinum (D) Nickel
Last Answer : (A) Alumina
Description : Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to ... Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction
Last Answer : (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot
Description : Which of the following ingredient of cement when added in excess quantity, causes the cement to set slowly. (a) Lime (b) Silica (c) Alumina (d) Iron oxide
Last Answer : Lime is a common ingredient in cement. It is typically added in small amounts to help the cement set more quickly. Adding too much lime can cause the cement to set slowly. Alumina, silica, and iron oxide are also common ingredients in cement, but they do not have an effect on the setting time.
Description : ___________ converts electrical energy into chemical energy. a) Galvanic cell b) Voltaic cell c) Electrolytic cell d) Leclanche cell
Last Answer : c) Electrolytic cell
Description : Mineral acids are also classified as: w) carboxyl acids x) inorganic acids y) non-electrolytic acids z) oxidation acids
Last Answer : ANSWER: X -- INORGANIC ACIDS
Description : Ionic substances dissolve in water to form: w) highly acid solutions x) electrolytic solutions y) colloids z) emulsions
Last Answer : ANSWER: X -- ELECTROLYTIC SOLUTIONS
Description : Which of the following metals is obtained from its most common ore using an electrolytic process? w) nickel x) tin y) aluminum z) manganese
Last Answer : ANSWER: Y -- ALUMINUM
Description : My theory of electrolytic dissociation earned me t 1903 Nobel Prize in chemistry. My name is: w) Niels Bohr x) Svante Arrhenius y) Michael Faraday z) John Cavendish
Last Answer : ANSWER: X -- SVANTE ARRHENIUS
Description : The main purpose of the auxiliary winding on a split-phase, single-phase motor is to _____________. A. limit the starting voltage B. increase the starting current C. start the motor D. keep the motor running in the event the main winding should fail
Last Answer : Answer: C
Description : a2–adrenergic receptors are associated with following except (a) Increase in phospholipase C activity (b) Increase in potassium channel conductance (c) Decrease in calcium channel conductance (d) Increase in adenylyl cyclase activity
Last Answer : Ans: D
Description : Most conducting materials such as copper, aluminum, iron, nickel, and tungsten _____________. A. increase in resistance with increased temperature B. increase in resistance with decreased ... C. decrease in resistance with increased temperature D. increase in conductance with increased temperature
Last Answer : Answer: A
Description : The film thickness for laminar film condensation on vertical surface __________ from top to bottom. (A) Cumulatively increases (B) Cumulatively decreases (C) Remain constant (D) And the surface conductance increase
Last Answer : (A) Cumulatively increases
Description : Pick out the wrong statement. (A) Lower boiling paraffins have higher octane number than higher paraffins (B) Dehydrogenation of naphthenes to aromatics is a desirable reaction in reforming ... is dearomatised kerosene (D) Catalyst used in catalytic reforming is platinum on silica-alumina base
Last Answer : (C) The most ideal feedstock for thermal reforming is dearomatised kerosene
Description : As compared to ordinary Portland cement, high alumina cement has (A) Higher initial setting time but lower final setting time (B) Lower initial setting time but higher final setting time (C) Higher initial and final setting times (D) Lower initial and final setting times
Last Answer : Answer: Option A
Description : What is the effect of adding a capacitor in series with an antenna? A. The antenna’s resonant frequency will increase B. The antenna’s resonant frequency will decrease C. The antenna will be physically 5% longer than its electrical length D. A capacitor is never added in series with an antenna
Last Answer : A. The antenna’s resonant frequency will increase
Description : Mental retardation in man, associated with sex chromosomal abnormality is usually due to (a) moderate increase in Y complement (b) large increase in Y complement (c) reduction in X complement (d) increase in X complement.
Last Answer : (d) increase in X complement.
Description : An Afro-Carribean male aged 48 years presents with gradual onset of exertional dyspnoea, non productive cough, malaise, weight loss and polyarthralgia. Schirmers test indicates a dry eye. X-ray ... 2) Serum phosphorus 3) Urea and electrolytes 4) Thallium Scan 5) Quantitative Immunoglobulins.
Last Answer : Answers-4 This condition is sarcoidosis. Serum calcium, Serum phosphorus, Chem7 and Chem 20 and Quantitative Immunoglobulins are all used in establishing the diagnosis. Gallium scan is helpful in ... areas of poor perfusion. It is particularly used in cardiology to detect areas of ischaemia.
Description : If a piece of metal at -20 degrees Celsius is added to an ice and water mixture in equilibrium at 0 degrees Celsius, the amount of ice will: w) Increase x) Remain the same y) Decrease
Last Answer : ANSWER: W -- INCREASE
Description : As shown in the illustration, part 'X' of the diagram is known as a/an _____________. EL-0052 A. commutator B. interpole C. starting pole D. auxiliary pole
Last Answer : Answer: B