Description : Classify Following oxides as Neutral, Acidic, Basic, and Amphoteric?
Last Answer : CO - neutral Sio2-acidic Pbo2-amphoteric
Description : What are amphoteric oxides?
Last Answer : Oxides of zinc and aluminium are called amphoteric oxides.
Description : Metallic oxides which react with both acid and base to produce salt and water are called A) Neutral Oxides B) Basic Oxides C) Amphoteric Oxides D) Acidic Oxides
Last Answer : C) Amphoteric Oxides
Description : The nature of calcium phosphate present in tooth enamel is (a)Basic (b)Acidic (c ) Neutral (d) Amphoteric
Last Answer : (a)Basic
Description : The chemical behaviour of morphine alkaloid is (A) acidic (B)Basic (C) neutral (D) amphoteric
Last Answer : (B)Basic
Description : What are amphoteric oxides? Choose the amphoteric oxides from amongst the following oxides: Na2O, ZnO, Al2O3, CO2, H2O -Chemistry
Last Answer : Those oxides which reacts with acids as well as bases to produce salts and water are called amphoteric oxides, e.g. Na2O, ZnO, are amphoteric oxides among given oxides.
Description : Which of the following oxides is amphoteric in nature ?
Last Answer : Which of the following oxides is amphoteric in nature ? A. `N_(2)O_(3)` B. `P_(4)O_(6)` C. `Sb_(4)O_(5)` D. `Bi_(2)O_(3)`
Description : What happens when concentrated hydrochloric acid is poured into a test tube containing zinc granules?
Last Answer : Zinc reacts with concentrated hydrochloric acid vigorously forming and the chemicals spill out of the test tube.
Description : What happens when heated aluminium powder is sprinkled into a jar of chlorine gas?
Last Answer : As heated aluminium powder comes in contact with chlorine, bright flashes are seen forming aluminium chloride.
Description : You are provided with magnesium ribbon and sulpher powder. Explain with the help of an activity that metal oxides are basic and non-metal oxide are acidic in nature. -Chemistry
Last Answer : Aim: To test the nature of oxides formed by metals and non-metals. Materials Required: Sulphur powder, Mg ribbon, water, blue litmus paper, red litmus paper. Procedure: 1.Take magnesium ribbon ... the metallic oxides are basic in nature whereas most of the non-metallic oxides are acidic in nature.
Description : Which of the following compounds on thermal decomposition yields as basic as well as acidic oxides ?
Last Answer : Which of the following compounds on thermal decomposition yields as basic as well as acidic oxides ? A. `Ca(OH)_(2) ... C. `K_(2)CO_(3)` D. `MgCO_(3)`
Description : Generally metallic oxides are basic and non-metallic are acidic in nature. Solution of which of the following oxides in water will change the colour of blue litmus to red? a)sulphur dioxide b)Magnesium oxide c)iron oxide d)copper oxide
Last Answer : a)sulphur dioxide
Description : What are the major constituents of typical fly ash particles generated from the combustion of coal? w) acidic and basic oxides x) trace elements y) unburned carbon z) sulfates and phosphates
Last Answer : ANSWER: W -- ACIDIC AND BASIC OXIDES
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 : 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 : 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.
Description : Mention the methods of obtaining ultra pure metal.
Last Answer : a) Fractional crystallization or zone refining. b) Vacuum melting c) Distillation d) Chemical vapour deposition e) Liquation process
Description : Name the process by which the refining of aluminium is done. Name the material used for the process.
Last Answer : Aluminium is refined by electrolytic refining. Carbon lining acts as the cathode and the graphite rods act as anode.
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 : What is cryolite? Write its chemical formula.
Last Answer : Cryolite is chemically sodium aluminium fluoride. Its molecular formula is Na3AlF6.
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 : What is the difficulty in obtaining aluminium from alumina?
Last Answer : Pure alumina melts at 2323K. At this temperature, aluminium vapourises and there will be considerable loss. It consumes more energy and also molten aluminium is not a very good conductor of electricity.
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 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 : What is alumina? Write its molecular formula.
Last Answer : Alumina is chemically hydrated oxide of aluminium. Its formula is Al2O3.2H2O.
Description : What is a mordant?
Last Answer : A mordant is a substance which helps to bind the dye to the cloth.
Description : Mention the uses of aluminium salts.
Last Answer : a) Aluminium salts are used as mordant in textile industry (to bind the dye to the cloth). b) Potash alum is used to prevent bleeding from small cuts by coagulating the blood at the surface.
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 : 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 : 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 : 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 : Why is flux used in the blast furnace?
Last Answer : Flux in extraction of iron is limestone. Limestone reacts with the sand present as impurity in the ore forming calcium silicate which is taken out of the blast furnace as slag.
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 : State the role of lime stone in the extraction of iron from haematite. Or Why is lime stone added during the extraction of iron?
Last Answer : Limestone reacts with the sand present as impurity in the ore forming calcium silicate which is taken out of the blast furnace as slag.