Metals react with air or oxygen to form metal oxide. For Example, Copper reacts with oxygen to form copper oxide. Metal + O2 → Metal oxide 2Cu + O2 → 2CuO 4Al + 3O2 → 2Al2O3
Oxides of metals can react with both acids and bases to produce salt and water. Such oxides are known as Amphoteric Oxides. Al2O3 + 6HCl → 2AlCl3 + H2O
Metals also reacts with water to form metal oxide. Metal oxide in turn can react with water to form metal hydroxide. For Example
2Na + 2H2O → 2NaOH + 1H2
2Al + 3H2O → Al2O3 + 3H2
Metals also reacts with dilute acids to form salt and hydrogen. For example, magnesium reacts with dilute hydrochloric acid to form magnesium chloride and hydrogen.
Metal + Acid → Metal Salt + Hydrogen
Mg + 2HCl → MgCl2 + H2
Chemical Properties of Non-metals-
Non-metals reacts with oxygen to form non-metal oxide.
Non-metal + Oxygen → Non-metal oxide
C + O2 → CO2
Non-metals do not react with water and acids to evolve hydrogen gas.
Non-metals can react with salt solution; more reactive element will displace the less reactive non-metal.
2 NaBr (aq) + Cl2(aq) → 2NaCl (aq) + Br2 (aq)
Non-metals can also react with hydrogen to form hydrides.
H2(g) + S(l) → H2S(g)
Alloys
Alloys are homogeneous mixtures of metal with other metals or nonmetals. Alloy formation enhances the desirable properties of the material, such as hardness, tensile strength and resistance to corrosion.
Examples of a few alloys: Brass: copper and zinc Bronze: copper and tin Solder: lead and tin Amalgam: mercury and other metal
Reactivity Series-
The series in which metals are arranged in the decreasing order of reactivity, it is known as Reactivity Series.
Ionic Compounds-
Compounds formed due to the transfer of electrons from a metal to a non-metal are known as Ionic Compounds.
Covalent Bond
Bond formed by sharing of electrons between the two atoms. They share their valence electrons to gain stability.
Properties of Ionic Compounds-
They are generally hard and solid.
They have a high melting and boiling point.
They are soluble in water but insoluble in inorganic solvents such as ether etc.
They are conductors of electricity in molten and solution state.
Occurrence of Metals
Elements or compounds which occurs naturally in earth crust are known as Minerals. Minerals from which pure metals can be extracted are known as Mineral Ores
Extraction of pure metals from its ores/steps for extraction of metals from its ore-
The first step is enrichment of the ore.
Second step includes extraction of metals
Third steps involve refining of metal
Gangue
Ores contain different impurities in it such as sand, soil etc. These impurities are known as Gangue.
Extracting Metals which are low in activity series-
Metals which are low in activity series are unreactive. The oxides of such metals can be reduced to metals by heating alone. For Example, Cinnabar (HgS)
Extracting Metals in the middle of the Activity Series
These metals are moderately reactive. They exists as sulphides or carbonates in nature. Before reduction, metal sulphides and carbonates must be converted into metal oxides. Sulphide ores are converted into oxides by heating strongly in presence of excess air, this is known as Roasting. Carbonate ores are converted into oxides by heating in limited air. This is known as Calcination.
Roasting
Calcination
Extracting metals towards the top of the activity series-
The metals are highly reactive. They cannot be obtained by heating. For Example, Sodium, magnesium and calcium are obtained by the electrolysis of their molten chlorides.
At cathode Na+ + e– → Na At anode 2Cl– → Cl2 + 2e–
Refining of Metals
Refining of impure metal is done using electrolytic refining. Impure copper is used as anode and strip of pure copper is used as Cathode. Acidified copper sulphate is used as electrolyte. When electric current is passed through this, impure metal from the anode gets deposited in the electrolyte solution, whereas pure metal from the electrolyte is deposited at cathode. Deposition of insoluble residue formed from the dissolution of anode during commercial electrolysis.
Carbon and its compound
Allotropes of Carbon
Different forms of an element that has same chemical properties but different physical properties are known as Allotropes. There are three allotropes of carbon- diamond, graphite and fullerene.
Diamond
Diamond exits as three-dimensional network with strong carbon-carbon covalent bonds. Diamond is hard in nature with high melting point.
It shines in presence of light and it is a bad conductor of electricity. The most common use of diamond is in making jewellery. It is also used in cutting and drilling tools.
Graphite
Graphite is made from weak van der wall forces. Each carbon atom is bonded with other three carbon atoms in order to form hexagonal rings. It serves as good conductor of heat and electricity. It is used as dry lubricant for machine parts as well as it is used in lead pencils.
Fullerene
It is a hollow cage which exits in the form of sphere. Its structure is similar to fullerene. But along with hexagonal rings, sometimes pentagonal or heptagonal rings are also present.
Two Important Properties of Carbon
Catenation is a property of carbon by which carbon atoms can link one another via covalent bond and can form long chains, closed ring or branched chains etc. Carbon atoms can be linked by single, double or triple bonds.
Carbon has a valency of 4 due to which it is known to have tetravalency. Due to this one carbon atom can bond with other 4 carbon atoms, with other atoms also such as Oxygen, Nitrogen etc.
Hydrocarbons
Compounds which are made up of carbon and hydrogen they are known as Hydrocarbons.
There are two types of hydrocarbons found Saturated Hydrocarbons and UnsaturatedHydrocarbons.
Saturated Hydrocarbons consist of single bonds between the carbon atoms. ForExample, Alkanes. Alkanes are saturated hydrocarbons represented by a formula, CnH2n+2.
Unsaturated Hydrocarbons are the one with double or triple bonds between the carbon atoms. For Example, Alkenes and Alkynes. Alkenes are represented as CnH2n whereas alkynes are represented as CnH2n-2. Some saturated hydrocarbons and unsaturated hydrocarbons are represented as –
Saturated hydrocarbons
Unsaturated hydrocarbons
Structure of hydrocarbons can be represented in the form of electron dot structure as well as open structures as shown below-
Carbons Compounds based on the basis of structure
Carbon Compounds can be classified as straight chain compounds, branched chain compounds and cyclic compounds. They are represented as
Straight chain carbon compound
Branched
Cyclic carbon compounds
Functional Groups
One of the hydrogen atoms in hydrocarbon can be replaced by other atoms according to their valencies. The atoms which decides the properties of the carbon atoms, are known as Functional Groups. For Example, Cl, Br, -OH, Aldehyde, Ketone, Carboxylic Acid etc.
Homologous Series
Series of compounds in which same functional group substitutes for the hydrogen atom in a chain of carbon.
Different functional groups
Chemical Properties of Carbon Compounds
Combustion
Carbon along with its compound is used as a fuel as it burns in presence of oxygen to release energy. Saturated hydrocarbons produce blue and non-sooty flame whereas unsaturated hydrocarbons produce yellow sooty flame.
CH4 + 2O2 → CO2 + 2H2O
Oxidation
Alcohol can be oxidized to aldehydes whereas aldehydes in turn can be oxidized to carboxylic acid. Oxidizing agent such as potassium permanganate can be used for oxidation.
Addition Reaction
Hydrogenation of vegetable oil is an example of addition reaction. Addition of hydrogen in presence of catalyst such as nickel or palladium. This converts oil into ghee.
Substitution Reaction
When one atom in hydrocarbon is replaced by chlorine, bromine, etc. this is known as Substitution Reaction.
Cleansing Action of Soap-When soap is added to water, the soap molecules uniquely orient themselves to form spherical shape micelles.
The non-polar hydrophobic part or tail of the soap molecules attracts the dirt or oil part of the fabric, while the polar hydrophilic part or head,(−COO−Na+), remains attracted to water molecules.
The agitation or scrubbing of the fabric helps the micelles to carry the oil or dirt particles and detach them from the fibres of the fabric.
Hard Water
It contains salts of calcium and magnesium, principally as bicarbonates, chlorides, and sulphates. When soap is added to hard water, calcium and magnesium ions of hard water react with soap forming insoluble curdy white precipitates of calcium and magnesium salts of fatty acids. These precipitates stick to the fabric being washed and hence, interfere with the cleaning ability of the soap. Therefore, a lot of soap is wasted if the water is hard.
Ethanol, C2H5OH is a colourless liquid having a pleasant smell.
It boils at 351 K.
It is ofmiscible with water in all proportions.
It is a non-conductor electricity (it does not contain ions)
It is neutral to litmus.
Uses:
As an antifreeze in radiators of vehicles in cold countries.
As a solvent in the manufacture of paints, dyes, medicines, soaps and synthetic rubber.
As a solvent to prepare the tincture of iodine.
How Do Alcohols Affect Human Beings?
If ethanol is mixed with CH3OH and consumed, it causes serious poisoning and loss of eyesight.
It causes addiction, damages the liver if taken in excess.
High consumption of ethanol may even cause death.
Reactions of Ethanol with Sodium-
Ethanol reacts with sodium to produce hydrogen gas and sodium ethoxide. This reaction supports the acidic character of ethanol.
2C2H5OH+2Na → 2C2H5ONa+H2(↑)
Elimination Reaction
An elimination reaction is a type of reaction in which two substituents are removed from a molecule. These reactions play an important role in the preparation of alkenes.
Dehydration Reaction
Ethanol reacts with concentrated sulphuric acid at 443 K to produce ethylene. This reaction is known as dehydration of ethanol because, in this reaction, a water molecule is removed from the ethanol molecule.
CH3CH2OH → CH2=CH2+H2O
(reaction taking place in presence of Conc.H2SO4)
Ethanoic Acid or Acetic
Molecular formula: CH3COOH
It dissolves in water, alcohol and ether.
It often freezes during winter in cold climate and therefore it is named as glacial acetic acid.
Esterification
When a carboxylic acid is refluxed with alcohol in the presence of a small quantity of conc.H2SO4, a sweet-smelling ester is formed. This reaction of ester formation is called esterification.
When ethanol reacts with ethanoic acid in presence of conc.H2SO4, ethyl ethanoate and water are formed. CH3COOH+C2H5OH → CH3COOC2H5+H2O
(reaction taking place in presence of Conc.H2SO4)
Saponification
A soap is a sodium or potassium salt of long-chain carboxylic acids (fatty acid). The soap molecule is generally represented as RCOONa, where R = non-ionic hydrocarbon group and −COO−Na+ ionic group. When oil or fat of vegetable or animal origin is treated with a concentrated sodium or potassium hydroxide solution, hydrolysis of fat takes place; soap and glycerol are formed. This alkaline hydrolysis of oils and fats is commonly known as saponification.
Reaction of Ethanoic Acid with Metals and Bases-
Ethanoic acid (Acetic acid) reacts with metals like sodium, zinc and magnesium to liberate hydrogen gas. 2CH3COOH+2Na→2CH3COONa+H2(↑)
It reacts with a solution of sodium hydroxide to form sodium ethanoate and water. CH3COOH+NaOH→CH3COONa+H2O
Reaction of Ethanoic Acid with Carbonates and Bicarbonates-
Carboxylic acids react with carbonates and bicarbonates with the evolution of CO2 gas. For example, when ethanoic acid (acetic acid) reacts with sodium carbonate and sodium bicarbonate, CO2 gas is evolved. 2CH3COOH+Na2CO3→2CH3COONa+H2O+CO2 CH3COOH+NaHCO3→CH3COONa+H2O+CO2
Catenation-
Catenation is the self-linking property of an element by which an atom forms covalent bonds with the other atoms of the same element to form straight or branched chains and rings of different sizes. It is shown by carbon, sulphur and silicon.
Write the answer of the following questions.
Which of the following is a non-metal? a) Sodium b) Chlorine c) Aluminium d) Copper
Which of the following metals is the least reactive? a) Sodium b) Zinc c) Copper d) Gold
Which of the following is a physical property of metals? a) Brittle b) Poor conductors of heat and electricity c) Malleable d) Non-lustrous
Which of the following is a chemical property of metals? a) High electronegativity b) Ability to form negative ions c) Reactivity with water d) Brittle nature
Which of the following is not a property of non-metals? a) Good conductors of heat and electricity b) Brittle c) Non-lustrous d) Poor conductors of heat and electricity
Which of the following non-metals is a good conductor of electricity? a) Oxygen b) Carbon c) Graphite d) Nitrogen
Which of the following metals is used for making wires? a) Aluminium b) Zinc c) Copper d) Iron
Which of the following non-metals is a gas at room temperature? a) Sulphur b) Bromine c) Iodine d) Carbon
Which of the following metals is the most reactive? a) Sodium b) Potassium c) Iron d) Silver
Which of the following non-metals is used in the manufacture of fertilizers? a) Oxygen b) Nitrogen c) Chlorine d) Fluorine
Which of the following metals is used for making coins? a) Iron b) Gold c) Aluminium d) Zinc
Which of the following non-metals is used as a disinfectant? a) Chlorine b) Nitrogen c) Oxygen d) Sulphur
Which of the following is an example of a metalloid? a) Sodium b) Carbon c) Copper d) Silver
Which of the following non-metals is used in the manufacture of soap? |a) Sulphur b) Oxygen c) Nitrogen d) Carbon
Which of the following metals is used for making aircraft parts? a) Aluminium b) Iron c) Gold d) Silver
Aluminium is used for making cooking uten¬sils. Which of the following properties of alu¬minium are responsible for the same? (i) Good thermal conductivity (ii) Good electrical conductivity (iii) Ductility (iv) High melting point
(a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (i) and (iv)
The most abundant metal in the earth’s crust is (a) Iron (b) Aluminium (c) Calcium (d) Sodium
The poorest conductor of heat among metals is (a) Lead (b) Mercury (c) Calcium (d) Sodium
Which property of metals is used for making bells and strings of musical instruments like Sitar and Violin? (a) Sonorousness (b) Malleability (c) Ductility (d) Conductivity
Which of the following is the correct arrange-ment of the given metals in ascending order of their reactivity? Zinc, Iron, Magnesium, Sodium (a) Zinc > Iron > Magnesium > Sodium (b) Sodium > Magnesium > Iron > Zinc (c) Sodium > Zinc > Magnesium > Iron (d) Sodium > Magnesium > Zinc > Iron
Which of the following pairs will give dis-placement reactions? (a) FeSO4 solution and Copper metal (b) AgNO3 solution and Copper metal (c) CuSO4 solution and Silver metal (d) NaCl solution and Copper metal
Non-metals form covalent chlorides because (a) they can give electrons to chlorine (b) they can share electrons with chlorine (c) they can give electrons to chlorine atoms to form chloride ions (d) they cannot share electrons with chlorine atoms
Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam? (a) FeO (b) Fe2O3 (c) Fe3O4 (d) Fe2O3 and Fe2O4
Which of tire following are not ionic compounds? (i) KCl (ii) HCl (iii) CCl4 (iv) NaCl
(a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iii)
The electronic configuration of three elements X, Y and Z are as follows: X = 2, 4, Y = 2, 7, Z = 2,1 Which two elements will combine to form an ionic compound and write the correct formula, (a) X2Y (b) YZ (c) XZ3</sub (d) Y2Z
The highly reactive metals like Sodium, Potas-sium, Magnesium, etc. are extracted by the (a) electrolysis of their molten chloride (b) electrolysis of their molten oxides (c) reduction by aluminium (d) reduction by carbon
Which of the following non-metal is lustrous? (a) Sulphur (b) Oxygen (c) Nitrogen (d) Iodine
Example of an amphoteric oxide is: (a) Na2O (b) K2O (C) Al2O3 (d) MgO
Which one among the following is an acidic oxide? (a) Na2O (b) CO (c) CO2 (d) Al2O3
The atomic number of an element ‘X’ is 12. Which inert gas is nearest to X? (a) He (b) Ar (c) Ne (d) Kr
The process in which a carbonate ore is heated strongly in the absence of air to convert it into metal oxide is called (a) Roasting (b) Reduction (c) Calcination (d) Smelting
Oxides of moderately reactive metals like Zinc, Iron, Nickel, Tin, Copper etc. are reduced by using (a) Aluminium as reducing agent (b) Sodium as reducing agent (c) Carbon as reducing agent (d) Calcium as reducing agent
In thermite welding a mixture of …… and …… is ignited with a burning magnesium ribbon which produces molten iron metal as large amount of heat is evolved. (a) iron (III) oxide and aluminium powder (b) iron (II) oxide and aluminium powder (c) iron (III) chloride and aluminium powder (d) iron (III) sulphate and aluminium powder
Galvanisation is a method of protecting iron from rudftng by coating with a thin layer of (a) Galium (b) Aluminium (c) Zinc (d) Silver
An element X is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following (a) Mg (b) Na (c) P (d) Ca
Reaction between X and Y forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z? (a) Has high melting point (b) Has low melting point (c) Conducts electricity in molten state (d) Occurs as solid
The electronic configurations of three ele¬ments X, Y and Z are X — 2, 8; Y — 2, 8, 7 and Z — 2, 8, 2. Which’of the following is correct? (a) X is a metal (b) Y is a metal (c) Z is a non-metal (d) Y is a non-metal and Z is a metal
Amalgam is an alloy of (a) Copper and Tin (b) Mercury (c) Lead and Tin (d) Copper and Zinc
Copper objects lose their shine and form green coating of (a) Copper oxide (b) Copper hydroxide and Copper oxide (c) Basic Copper carbonate (d) Copper carbonate