Metals And Non-metals

Metalloids refer to those class of material which possess properties of both the metals and non-metals. Examples of such materials are silicon, germanium etc. They possess fair conductivity of electricity or heat and are brittle in nature etc.

Among all the metals in their pure form, Tungsten has the highest melting point which is around 3422° C and this is the reason why it is used in the making of incandescent bulb filaments.

Some metals melt on keeping them on palm because such metals have very low melting point compared to other metals. Examples of such metals are Gallium and caesium.

Reactive metals like sodium and potassium react very violently with oxygen or water and hence the reaction can even catch fire. To prevent such an accidental reaction or fires, metals are kept immersed in kerosene oil.

Based on the description of the metal that it is reactive with water or air and it can be cut with a knife, the metal X is surely sodium as sodium possess all these properties.

Less reactive metals do not displace hydrogen from the acids. Reactive metals like sodium, magnesium etc displace hydrogen from acids to form respective chlorides.

Reaction:

2Na + 2HCl → 2NaCl + H₂

Mg + 2HCl → MgCl₂ + H₂

Gold and Platinum belong to class of noble metals in the sense that gold and platinum do not react with almost any chemical reagent.

Aqua Regia is the chemical mixture which consists of 3 parts of concentrated hydrochloric acid and 1 part of concentrated nitric acid and this mixture can dissolve gold and platinum. The reaction is as follows:

Au + HNO₃ + 4 HCl → HAuCl₄ + NO + 2 H₂O

Lustre means the shine which is possessed generally by all the metals. Non-metals generally do not possess any kind of lustre.

Example of non-metals which possess lustre are carbon as diamond and iodine.

(a) Diamond is the hardest known naturally occurring non-metalic substance.

(b) Graphite, an allotrope of carbon is a non-metal which is a good conductor of heat and electricity.

Except for carbon all the non-metals are below hydrogen in the activity series of the elements because of which Non-metals do not evolve hydrogen gas when react with water, steam or dilute acids.

The best example of a displacement reaction for a non-metal is the reaction in which the more reactive halogen replaces the less reactive ones. The reaction is as follows:

Cl₂ + 2NaBr → 2NaCl + Br₂

(i) When Sulphur reacts with concentrated nitric acid, sulphuric acid, nitrogen dioxide and water are formed as the products. The reaction is as follows:

S + 6HNO₃→ H₂SO₄ + 6NO₂ + 2H₂O

(ii) When white phosphorous reacts with concentrated sulphuric acid the products formed are phosphorous acid and Sulphur dioxide. The reaction is as follows:

P₄ + 6H₂SO₄→ 4H₃PO₃ + 6SO₂

(iii) When phosphorous reacts with concentrated nitric acid formation of phosphoric acid, nitrogen dioxide and water takes place. The reaction is as follows:

P + 5HNO₃→ H₃PO₄ + 5NO₂ + H₂O

Non-metals typically have larger sizes as compared to the metals because of which to attain a stable noble gas configuration, it is difficult for a non-metal to lose electrons and on the other hand they can easily accept electrons with less energy involved to fill the octet.

Hence non-metals gain electrons to form anions.

Ionic Bond is a type of chemical bond which exists between two oppositely charged species and the bond is mainly formed between electron donor element and electron acceptor element.

Example- NaCl, KBr etc.

In example of NaCl, Sodium atom donate one electron to chlorine atom to form ionic bond.

Water helps in separation of oppositely charged ions from their ionic state because when an ionic is dissolved in water the ions get attracted by the water molecules which leads to the dissociation of ionic compound.

In Ionic compounds, ions are held tightly together by strong electrostatic forces of attraction making them quite rigid and hence even when a small force is applied to the compound, the force causes the ions to get displaced from the lattice and they suffer repulsion from similar charged ions in the lattice causing the ionic solids to shatter.

In Ionic compounds, ions are held tightly together by strong electrostatic forces of attraction making them quite rigid. So these ions do not conduct electricity in solid state due to the immobility of the ions. But in molten state the ions get some free space to move as the electrostatic force of attraction weakens and hence allow the conduction of electricity.

Calcination is one of the processes of metallurgy in which the metals are heated at high temperatures in the absence or limited supply of air to get rid of the volatile substances and to convert the metal to its oxide.

Carbonates, Bicarbonates and hydroxide ores generally undergo calcination.

Reaction:

In electrolytic reduction of NaCl, metal is deposited at the cathode and chlorine is liberated at the anode.

Sodium being electropositive in nature gets attracted to the negative electrode cathode and chlorine being electronegative in nature gets attracted to positive electrode anode.

The two metals which can be refined electrolytically are copper and zinc.

The word electroplating can be broken into two words electro which means using electricity and plating means to coat.

Hence electroplating is a process of coating a metal object with another metal like zinc, chromium etc by the process of electrolytic deposition in order to protect the base metal.

Metal surface when exposed to environment, there are chances that the oxygen or moisture present in the environment to react with the metal making the metal corroded.

In order to protect the metal from environmental factors the metal is painted.

Galvanization is a process of coating a metal especially iron object with zinc metal.

Zinc is the metal which is used for coating and iron objects are generally galvanized to protect them from rust.

Noble metals like gold and platinum which are unreactive under normal conditions are the elements which are resistant to corrosion.

The special quality of the iron pillar at Qutub Minar is that the pillar is not rusted or rather the pillar is rust resistant which depicts the high-quality craftsmanship of Indian craftsman.

Atomic Number of X = 3

Atomic Number of Y = 1

Atomic Number of Z = 9

Among the given elements, element X is a metal as it can easily lose one electron to achieve the stable noble gas configuration of helium. Element X is Lithium.

Element Z will be a non-metal as it can easily accept an electron to achieve the stable noble gas configuration of neon.

Sea water contains many dissolved salts but the slat which is abundant in seawater is sodium chloride.

So Sodium and chlorine are obtained on a large scale from sea water.

Other salts in sea water are MgCl₂, CaCl₂ etc.

Concentration is a process of removal of impurities from the ores. Sulphide ores are normally concentrated by the process of Froth Flotation as these ores possess good wetting and froth forming properties when mixed with frothing agents.

Element which is cheaper than aluminium and can be used for the reduction purposes is carbon. Carbon reacts with metallic oxides to form carbon dioxide and metal is obtained.

Carbon is added to the molten iron to improve the properties of iron and it basically enhances the strength, hardness and corrosion resistance property of iron.

Noble metals like gold and platinum which are unreactive under normal conditions and hence are found in free-state.

On the other hand, aluminium is reactive in nature and hence react with environmental factors like oxygen or moisture to form corresponding products.

Sodium atom contains total 11 electrons whereas sodium ion is formed by the loss of one electron and hence sodium ion contain total 10 electrons which is similar to the noble gas configuration of neon.

Except for carbon all the non-metals are below hydrogen in the activity series of the elements because of which Non-metals do not evolve hydrogen gas when reacting with water, steam or dilute acids. To displace hydrogen from the non-metal should be placed above hydrogen in the activity series.

(i) Mercury is a metal which does not stick to glass as mercury lacks adhesive forces.

(ii) Zinc Oxide is amphoteric in nature which means it can act as an acid as well as a base in a chemical reaction depending upon the reaction conditions.

(iii) A pure metal will be deposited at cathode because cathode is a negative electrode and hence it attracts the positive metal ions from the electrolyte.

(iv) Carbon Monoxide will change the color of the blue litmus if the litmus paper is moist as carbon monoxide will dissolve in the water molecules to form weak acid.

Though zinc is more reactive than iron but when a layer of zinc is exposed to the atmosphere zinc reacts with the oxygen in the atmosphere to form zinc oxide. This zinc oxide forms a protective layer on the surface of zinc which prevents the further attack. Hence zinc is used to galvanize iron.

(i) The reaction is as follows:

3Fe + 4H₂O → Fe₃O₄ + 4H₂

(ii) The reaction is as follows:

Ca + 2H₂O → Ca (OH)₂ + H₂

(iii) The reaction is as follows:

2K + 2H₂O → 2KOH + H₂

Aluminium has far greater affinity for oxygen as compared to carbon because of which carbon cannot separate oxygen from aluminium oxide. Hence Al metal cannot be obtained by the reduction of Al₂O₃ with coke.

In terms of reactivity o iron and copper, iron is more reactive than copper because of which iron reacts with the copper sulphate solution to form ferrous sulphate leaving holes in the iron pot. The reaction is as follows:

Fe + CuSO₄→ FeSO₄ + Cu

The three properties of sodium are as follows:

1. Sodium is very soft in nature and it can be easily cut with the help of a knife.

2. It is non-sonorous metal which means it does not make sound on being hit by hard object.

3. It has low melting and boiling points.

Since the ore on heating in air gives Sulphur dioxide which means that the ore is a sulphide ore. The various methods involved in the extraction of metals from sulphide ores are as follows:

1. The ore is concentrated by the process of froth flotation to remove the impurities.

2. The concentrated ore is then heated in presence of air to convert the ore to corresponding metal oxide.

3. The metal oxide is then made to react with carbon to reduce the metal oxide to corresponding metal.

4. The metal is then purified by electrolytic reduction.

In the first reaction zinc is more reactive than copper and hence the above reaction is possible as zinc can replace copper from copper sulphate to form zinc sulphate.

In the second reaction, it is known that iron is less reactive than zinc and hence iron cannot replace zinc from zinc sulphate.

The non-metal which is the largest constituent of air is Nitrogen.

When nitrogen is heated with hydrogen in the ratio of 1:3 in presence of iron as a catalyst we get ammonia as the product. This process of ammonia production is called as Haber’s process. The reaction is as follows:

N₂ + 3H₂→ 2NH₃

When nitrogen is heated with oxygen, it gives nitrogen dioxide. The reaction is as follows:

N₂ + 2O₂→ 2NO₂

When nitrogen dioxide is dissolved in water, it gives nitric acid which is a strong oxidizing agent. The reaction is as follows:

3NO₂ + H₂O → 2HNO₃ + NO

(i) Therefore from above reactions we can easily state that,

A is Nitrogen

B is Ammonia

C is Nitrogen Dioxide

D is Nitric Acid

(ii) The non-metal that is nitrogen belongs to the group 15 of the periodic table.

(i) The use of argon is as follows:

Argon is inert in its nature and hence it is used in filament bulbs to provide the inert medium and to avoid the burning of the metal.

The use of Krypton is as follows:

Krypton is also used in fluorescent bulbs, flashbulbs and lasers. Lamps filled with krypton are used as approach lights at airports as the light from these lamps can travel far even in dense fog.

(ii) Helium is generally added to protect the divers from the toxic effects of nitrogen and the percentage of helium is 11.7%.

Zinc, Copper as well as silver are less reactive as compared to aluminium and hence cannot displace aluminium from its salt as they are placed below aluminium in activity series.

So the correct answer is d.

The activity series of metals is as follows:

From the sets of reactions i, ii, iii, it can be observed from i and ii that X is more reactive than Y and hence it displaces Y from its salt.

From reaction iii it can be observed that Z is more reactive than X as it displaces X from its salt.

So the most reactive element is Z and the least reactive is Y.

So correct answer is d [Z and Y].

The element with atomic number of 13 [2 + 8 + 3 = 13] is Aluminium and it is more reactive than zinc.

The ore of aluminium is called as bauxite and the oxide of aluminium is Al₂O₃.

So the correct answer is d.

The metallic oxide of type MO which reacts with moisture and carbon dioxide of atmosphere to form basic carbonate is copper oxide. Copper metal on exposed to atmosphere reacts with oxygen, moisture and carbon dioxide to form a green coloured coating of copper carbonate and copper hydroxide.

So the correct answer is a.

Among all the available metal solutions, copper is more reactive as compared to silver only. Copper cannot displace zinc or iron from its salt as it is less reactive as compared to both the metals. So blue colour will appear only in the beaker which has Silver nitrate solution in it.

So the correct answer is b.

Iron is more reactive than copper and hence it can displace only copper from its salt. Iron is less reactive as compared to aluminium or zinc so they will not be displaced from their salts. Also iron will not react with its own salt. So the reddish brown coating on surface of nail is of copper deposition which will be observed only in case of iron nail dipped in copper sulphate solution.

So the correct answer is c.

Among all the reactions, the reaction d is only not possible because silver is less reactive as compared to copper and hence it cannot displace copper from its salt.

So correct answer is d.

Many of the metallic oxides react with the hydrogen to form respective hydrides and hence hydrogen is not widely used as reducing agent in metallurgy.

So the correct answer is d.

Among all the available options Steel is the alloy of iron which contains the non-metal carbon in it.

Bronze consists primarily of copper and 12% tin

Brass is an alloy of copper and zinc.

Amalgam is an alloy of mercury.

So the correct answer is d.

The metallic oxide of the form E₂O₃ is Iron [III] Oxide. Iron reacts with chlorine to form different Iron [II] Chloride and Iron [III] Chloride. The ore of Iron that is Fe₂O₃ Haematite does not react with water.

So the correct answer is d.