Give reason: Some metals are more reactive than others.

1 Answer

Answer :

Metals are electropositive and have tendency to donate electrons. Some elements give up their valence electrons and hence more reactive.

Related questions

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 : Give reason: a) Metals are electropositive. b) Non-metals are electronegative. c) Even though hydrogen is a non-metal, it is electropositive. d) Sodium is electropositive.

Last Answer : a) Metals are electropositive. Electropositive element has the tendency to lose electrons and form cation.Metals are electron donors. Hence they are electropositive. b) Non-metals are ... is electropositive because donates electrons from last orbit to another element and becomes electropositive.

Description : In a solution of silver nitrate, a copper plate was dipped. After some time, silver from the solution was deposited on the copper plate. Which metal is more reactive – copper or silver?

Last Answer : More reactive metal displaces a less reactive metal. Hence copper metal is more reactive.

Description : Name some metals which do not displace hydrogen from dilute acids.

Last Answer : Platinum, gold, silver, mercury & copper do not displace hydrogen from dilute acids.

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 : 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 : How do metals react with sulphur?

Last Answer : Metals react with sulphur forming respective sulphides. Iron reacts with sulphur forming ferrous sulphide.

Description : How do metals react with chlorine?

Last Answer : Metals react with chlorine to form respective chlorides. Aluminium reacts with chlorine to form aluminium chloride.

Description : How do metals react with hydrogen?

Last Answer : Metals react with hydrogen to form respective hydrides. Calcium reacts with hydrogen to form calcium hydride.

Description : How do metals react with nitrogen?

Last Answer : Metals react with nitrogen forming respective nitrides at high temperature. Magnesium reacts with nitrogen to form magnesium nitride.

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 : Metals

Last Answer : Examples of metals include copper (Cu), zinc (Zn), gold (Au), silver (Ag), tin (Sn) and lead (Pb). The following are some of the properties of metals: Thermal conductors Metals ... are nonmagnetic. You can see how the properties of metals make them very useful in certain applications.

Description : Metals, Metalloids and Non-metals

Last Answer : The elements in the periodic table can also be divided according to whether they are metals, metalloids or non-metals. The zigzag line separates all the elements that are metals from those that ... more metals then non-metals. Metals, metalloids and non-metals all have their own specific properties.

Description : Describe the effects of temperature on conductivity of metals.

Last Answer : For metallic conductors, the resistance of all pure materials increases linearly with temperature over a limited range of temperature hence conductivity decreases. For metallic conductors, ... vibrating ions collide with the moving electrons. Hence resistance increases with increasing temperature.

Description : With rise in temperature the resistance of pure metals?

Last Answer : With rise in temperature the resistance of pure metals increases.

Description : Give reason: Gold occurs in native form.

Last Answer : Gold is low in the reactivity series. It is least reactive or unreactive. Hence gold is found in free state.

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 : Give reason: Magnesium ribbon should not be kept near bottles containing volatile chemicals.

Last Answer : Magnesium is a reactive metal therefore it should not be kept near bottles containing volatile chemicals.

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 : Give reason: Metallic articles which are exposed to air over long period of time lose their lustre.

Last Answer : Due to the formation of oxide, hydroxide and carbonate layers.

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 : 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 : 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.