Description : What happens when lime stone is not added during the extraction of iron?
Last Answer : If limestone is not added to charge during the extraction of iron, the blast furnace will get blocked.
Description : In the extraction of iron from haematitie, the charge used is haematite, coke and lime stone in the following weight ration
Last Answer : In the extraction of iron from haematitie, the charge used is haematite, coke and lime stone in the following weight ration ... C. `8:1:4` D. `1:4:8`
Description : What is the role of coke in the extraction of iron?
Last Answer : Coke is a good reducing agent. It reduces iron oxide to iron. It is also a good fuel which supplies heat energy for the chemical reactions.
Description : What is the role of molten cryolite in the extraction of aluminium?
Last Answer : When pure alumina is mixed with molten cryolite, it forms an electrolyte at 1223K. Molten cryolite also acts as a solvent for alumina.
Description : Why is extraction of aluminium not commercially viable by using reducing agents like coke? OR Coke is used in the extraction of iron but not in the extraction of aluminium. Why? OR Aluminium cannot be extracted by heating bauxite and coke. Why?
Last Answer : Oxygen of aluminium oxide cannot be easily taken away by reducing agents like coke.
Description : How is the slag obtained in the extraction of iron useful?
Last Answer : Slag obtained in blast furnace is used as one of theraw materials of glass and cement.
Description : What happens when? a) A cleaned iron plate or iron nail is kept in 10g of copper sulphate solution. b) A pinch of mercuric oxide is kept in a test tube. c)A small crystal of silver nitrate is dissolved in distilled water and a drop of ammonium hydroxide & a pinch of glucose powder are added.
Last Answer : a) A cleaned iron plate or iron nail is kept in 10g of copper sulphate solution. After a few hours a coating of copper is seen on iron nail/plate. It is based on displacement reaction. ... on the inner walls of the test tube. Aldehyde group in glucose reduced silver nitrate to metallic silver.
Description : Briefly explain the extraction of aluminium from alumina with chemical equations.
Last Answer : Aluminium oxide dissolved in molten cryolite is taken in a chamber with gently sloped base.The inner wall is made of carbon lining. Graphite rods are introduced in the electrolyte bath. The carbon lining ... is passed. Molten aluminium collects at the lining and flows out of the gently sloped base.
Description : Why is pure alumina needed for the extraction of aluminium?
Last Answer : For electrolysis of we need pure alumina. Hence bauxite is converted into alumina by chemical process.
Description : Why lime stone is added in the extraction of lead from galena ?
Last Answer : Why lime stone is added in the extraction of lead from galena ? A. It prevents the formation of ... moves the impurity of iron oxide as fusible slag.
Description : Why lime stone is added in the extraction of lead from galena?
Last Answer : Why lime stone is added in the extraction of lead from galena? A. It prevents the formation of ... moves the impurity of iron oxide as fusible slag.
Description : Why is 6% to 8% copper added to gold in making ornaments?
Last Answer : Pure gold is very soft, it cannot be used to make artistic ornaments. To make it hard, improve the looks and colour, 6 to8% copper is added to ornamental gold.
Description : Give reason: a) Iron exposed to air rusts quickly during rainy season.
Last Answer : a) Iron exposed to air rusts quickly during rainy season. Due to the presence of excess water vapour. b) Iron nail kept in a closed jar containing calcium chloride does not rust. As air is dry ... ) Tin is used to coat the inner walls of brass and copper utensils. To avoid corrosion or rusting.
Description : The main reactions occuring in blast furnace during extraction of iron from haematite ore…..
Last Answer : The main reactions occuring in blast furnace during extraction of iron from haematite ore .. A. `Fe_(2)O_ ... 3Cto2Fe+3CO` D. `CaO+SiO_(2)toCaSiO_(2)`
Description : The slag formed in the blast furnace during the extraction of iron from haematite is
Last Answer : The slag formed in the blast furnace during the extraction of iron from haematite is A. `Ca_(3)(PO_(4))_(2)` ... (3)` C. `FeSiO_(3)` D. `MnSiO_(3)`
Description : If the iron ore contains clay as an impurity, the flux added during calcination, is (A) Clay (B) Lime stone (C) Argillaceous iron ore (D) All the above
Last Answer : Answer: Option B
Description : Name the impurities present in cast iron. How can these impurities be removed?
Last Answer : Cast iron contains sulphur, phosphorous, silicon and carbon. The impurities present in the blast furnace can be removed by using Bessemer converter, open hearth process or electric furnace.
Description : Mention the uses of cast iron.
Last Answer : Cast iron is used for: a) Making stands for wooden benches and desks. b) Making dosa pan c) Making lid for covering manholes of sewage system. d) Making machinery parts.
Description : Why is slag collected above molten iron?
Last Answer : Slag is lighter than molten iron and collects above molten iron. Slag prevents oxidations of molten iron back into iron oxide.
Description : How is iron ore concentrated?
Last Answer : The chief ore of iron is haematite. Haematite ore is concentrated by hydraulic washing. The crushed ore is washed with a stream of water, lighter gangue particles will be washed away and the heavy iron ore particles also with silica settles down during washing.
Description : Give reason: Iron displaces copper from copper sulphate solution.
Last Answer : Iron is more reactive than copper. Hence it displaces copper from copper sulphate solution.
Description : Give reason: Aluminium / Iron become passive when immersed in concentrated nitric acid.
Last Answer : Since concentrated nitric acid is a powerful oxidising agent, it forms a protective oxide layer on the metal instantly
Description : What happens when a iron nail or a piece of aluminium wire is dipped in concentrated nitric acid?
Last Answer : Iron nail or aluminium wire does not react with concentrated nitric acid. It makes iron more passive.
Description : Give reason: a) Magnesium reacts more vigorously with hydrochloric acid than zinc or copper. b) Iron takes more time to react with dilute hydrochloric acid than magnesium and zinc
Last Answer : a) Magnesium reacts more vigorously with hydrochloric acid than zinc or copper. The reactivity of magnesium is higher than that of zinc. Hence it reacts with hydrochloric acid more vigorously. b) ... acid than magnesium and zinc As iron has lowest reactivity when compare to magnesium and zinc.
Description : Why is iron grill painted frequently?
Last Answer : To prevent rusting of iron.
Description : What are the methods of preventing rusting of iron?
Last Answer : Iron articles can be coated with zinc or chromium. By painting the iron articles. By heating and dipping in molten coal tar.
Description : The reaction (s) which does (do) not occur in the reduction zone in the extraction of iron from haematite ore is (are)
Last Answer : The reaction (s) which does (do) not occur in the reduction zone in the extraction of iron from haematite ore ... ` D. `CaO + SiO_(2) rarr CaSiO_(3)`
Description : Consider the following statements and arrange in the order of true/false as given in the codes.`S_(1)`: In extraction of iron from haematite ore, the
Last Answer : Consider the following statements and arrange in the order of true/false as given in the codes.`S_(1)`: In ... `. A. TFTT B. FTFF C. FFTT D. TFFT
Last Answer : The reaction (s) which does (do) not occur in the reduction zone in the extraction of iron from haematite ore ... ` D. `CaO + SiO_(2) rarr CaSiO_(2)`
Description : Consider the following statements in the extraction of iron from haematite: (I) `CO`is the main reducing agent (II) `Fe_(2)O_(3)`is used to oxidise th
Last Answer : Consider the following statements in the extraction of iron from haematite: (I) `CO`is the main reducing agent (II) ... I, II and III D. I, II and IV
Description : The flux used in the extraction of iron from Haematite in te blast furnace is `"["EAM(ENG)2014"]"`
Last Answer : The flux used in the extraction of iron from Haematite in te blast furnace is `"["EAM(ENG)2014"]"` A. Lime stone B. Silica C. Coke D. CO
Description : __________ is used as a flux in the extraction of iron from iron ore (haematite) in blast furnace. (A) Bauxite (B) Limestone (C) Quartz (D) Manganese
Last Answer : (B) Limestone
Description : Give reason: During burning of magnesium not only magnesium oxide is formed but also magnesium nitride is formed.
Last Answer : Due to high temperature the triple bond between nitrogen atoms is broken and a small quantity of magnesium nitride is formed.
Description : science Topic : Metals Fill in the blanks.
Last Answer : 1. An example of a liquid metal is Mercury/gallium. 2. A metal which is soft is sodium. 3. A metal which lacks ductility is sodium. 4. A non-metal which is lustrous is graphite/iodine ... 59. Aluminium+ copper+ magnesium+ manganese is useful in making aircraft bodies. 60. Ornamental gold is an alloy
Description : What are memory alloys? How are they useful?
Last Answer : Certain alloys which regain their original shape when deformed are called memory alloys. Preparation of memory alloys saves energy of melting and recasting of used articles.
Description : Write a note on contributions of Indians to metallurgy.
Last Answer : a) Romans used armour and cutlery made from Indian iron. b) Indian metallurgist Nagarjuna wrote the book Rasaratnakara' in 9th century BC which explained the preparation of various metallic ... near Qutab Minar constructed by Vikramadithya about 1600 years ago has withstood the action of weather.
Description : Which metal is present both in brass and bronze?
Last Answer : Copper
Description : What property of invar steel is used in making pendulums and measuring tapes?
Last Answer : Invar steel has the least co-efficient of linear expansion.
Description : What property of stainless steel is used in making surgical instruments?
Last Answer : Surgical steel is not attacked by mild chemicals easily and it does not corrode.
Description : How are the properties of alloys different from those of metals?
Last Answer : Copper is reddish and zinc is grayish in colour where as brass which is an alloy of copper and zinc is golden yellow in colour. Iron is a magnetic substance but stainless steel, an alloy of iron is non magnetic.
Description : Give reason: Metals belonging to the same group form good alloys.
Last Answer : As metals belonging to the same group in the periodic table have similarities in electronic configuration.
Description : Why are alloys made?
Last Answer : Alloys give desired properties to the metal. It improves the properties of metals.
Description : How is an alloy formed?
Last Answer : Alloysare prepared by mixing the various metals in their molten state and cool them to room temperature. Better quality can be made by mixing metals using ultrasonics.
Description : What is an alloy?
Last Answer : An alloy is a homogenous mixture of two or more metals or metal with a non-metal. Example: Brass is an alloy of two metals copper and zinc. Steel is an alloy of a metal iron and non-metal carbon.
Description : Briefly explain the electrolytic refining of copper.
Last Answer : Copper is purified by electrolytic refining. The apparatus consists of an electrolytic tank containing copper sulphate solution as electrolyte. A set of thick blocks of impure copper is made anode ... anode becomes thinner and pure cathode becomes thicker. The impurities collect at the bottom.
Description : What is electrolytic refining?
Last Answer : Electrolytic refining is a technique of ultra refining of metal. In this method, impure metal is taken as anode and pure metal are taken as cathode. Electric current is passed through the electrolyte to obtain pure metal at the cathode.
Description : Explain the process of zone refining. Name one metal refined by this method.
Last Answer : The apparatus used for zone refining consists of a circular heater fitted around the rod of impure metal at one end. The circular heater is slowly moved to the other end. At the heated zone, ... in solid metal passes into the adjacent molten part. A metal refined by zone refining is germanium.
Description : What is meant by zone refining or fractional crystallization?
Last Answer : Zone refining is a technique of obtaining ultra pure metal. It is based on the principle of differences in solubility of impurities in liquid and solid states of the metal.
Description : What is meant by liquation process?
Last Answer : Liquation is a process of obtaining ultra pure metal. It is based on the principle that metals are readily fusible where as the impurities are infusible at the temperature at which the metals fuse.