First Term Flashcards
Covalent bond
The bond formed between two atoms by mutual sharing of electrons between them so that the combining atoms acquire noble gas configuration is called a covalent bond
Ionic bond or electrovalent bond
The bond formed by the complete transfer of one or more electrons from one atom to another so that the combining atoms acquire noble gas configuration.
Electronaffinity
Amount of energy required to add an electron in its outer most shell.
Electronegativity
Tendency of an atom to attract shared pair of electron towards itself.
Polarization is generated in water due to difference in E.N of atoms, oxygen and hydrogen.
Organic compounds are treated as non-polar compound, due to very less difference of of E.N between carbon and hydrogen.
Hund’s rule
Half-filled and full-filled orbitals are highly stable
Like dissolve like
Non-polar compound dissolves in non-polar solvent.(organic compound)- benzene, ethyl, acetate, alcohol, CHCl3.
Polar compound dissolves in polar solvent. Inorganic compound- water
Nascent hydrogen
Hydrogen produced at the moment of it’s birth due to chemical reaction is known as nascent hydrogen. It is always produced in solution in contact with the substance to be reduced.
I. When molecular hydrogen gas is passed through yellowish brown colour of ferric chloride (FeCl3) , there is no any change in colour observed but when ferric chloride is alidified and added some granulated zinc, the colour of ferric chloride is discharged.
FeCl3+H2—————–>no reaction
dil.H2SO4+2H————>ZnSO4+2[H]
2FeCl3+2[H]—————>FeCl2+2HCl
Yellowish ferrous
Brown chloride
Colour (colour is discharged)
II. When molecular hydrogen is passed through KMnO2 solution having pink colour observed i.e. no any reaction occurs.
KMnO2+H2————–>no change
Pink color
But when the solution of KMnO2 is alidified with the addition of dil.H2SO4 and added some pieces of granulated zinc, the pink colour of KMnO2 is discharged.
Zn+dil.H2SO4————–>ZnSO4+2[H]
2KMnO4+dil.3H2SO4+10[H]————–
Pink colour
——–>K2SO4+2MnSO4+8H2O
Pink colour is discharged
III. When K2Cr2O7(potassium dichromate) is treated with molecular hydrogen, the orange colour of K2Cr2O7 does not change i.e there is no reaction.
K2Cr2O7H2—————>no reaction
But when K2Cr2O7 is alidified with dil.H2SO4 and added some pieces of granulated zinc, the orange colour of K2Cr2O7 is discharged. Zn+dil.H2SO4————->ZnSO4+2[H]
K2Cr2O7+4H2SO4+6[H]——————-
Orange colour
——–>K2SO4+Cr2(SO4)3+7H2O
Orange colour is discharged
Atomic hydrogen
Atomic hydrogen is obtained when molecules of hydrogen is dissociated by providing the required amount of energy.
3000°C
H-H ————–>H+H + 104 kcal
Molecular atomic
Hydrogen hydrogen
Preparation of atomic hydrogen
When molecular hydrogen is passed through not electric arc at 3000°C between two tungsten electorals, atomic hydrogen is obtained.
Thus, produced atomic hydrogen can reduce the chloride and oxides of metals into metals.
AgCl + H ———> Ag + HCl
CuO + 2H ———-> Cu + H2O
Calcium Sulphide and Barium Sulphate are reduced by atomic hydrogen into Cadmium and Barium Sulphide.
CdS + 2H ————-> CD + H2S
BaSO4 + 8H ———-> BaS + 4H2O
Carbon monoxide is reduced by atomic hydrogen into formaldehyde.
O
||
CO + 2H ————–> H-C-H
Isotopes
The atoms of same element having same atomic number but different atomic mass are called isotopes.
Protium
It has one electron and one proton in it’s nucleus.
Uses of protium
I. It is used in the manufacture of ammonia by haber’s process.
Fe - Mo
N2 + 3H2 <-------_-> 2NH3
300-500°C
200-900 atm
II. In the hydrogenation of vegetable oils to form solid fats i.e. vanaspati ghee.
III. It is used in oxyhydrogen torch and atomic hydrogen torch for wielding purposes.
Deuterium
I. It is used as a solvent for H-nuclear magnetic resonance spectroscopy.(study of peak)
II. It is used in the preparation of hydrogen bomb.
2 3 4 1
H + H ———-> He+ n+energy
1 1 2 0
Deuterium tritium
Tritium
I. It is used as artificial tracer in chemistry , biology and medicine.
II. It is used as a neutron initator in nuclear fusion reaction.
Heavy water (D2O)
Ordinary water contains traces of D2O. D2O is one part in six thousand parts. It has been estimated that about 29 thousand litre of water must be electrolized to get one litre of heavy water. Heavy water is colourless, tasteless and odourless.
Uses of heavy water:-
I. It is used in the preparation of deuterium(heavy hydrogen)
II. It is used as a tracer compound in determining the mechanism of many organic reaction.
III. Heavy water slow downs the fast moving neutrons and thus, helps in controlling the nuclear reaction.
Physiological effect of heavy water:-
I. Mice and rat feel thirstier on drinking heavy water.
II. Growth of bacteria is considerably stopped.
III. Tobacco seeds do not grow in D2O.
IV. Tadpole and protozoa die in almost pure heavy water.
Oxides
Binary compound in which at least one atom should be oxygen is called oxygen. Eg:- SO2, SO3, Na2O, Fe2O3, P2O5, etc
Classification of oxides:-
1. Acidic oxides- Generally, oxides of non metals are called acidic oxides. When acidic oxides are dissolved in water it gives acid. Eg:-
CO2 + H2O——————->H2CO3
SO3 + H2O——————->H2SO4
Acidic oxides react with base to give salt and water
SO2 + 2NaOH———->Na2SO3 +H2O
Sodium sulphide
- Basic oxides:- generally, oxides of metals are basic oxides. When basic oxides are dissolved in water , it gives base. Eg:-
Na2O + H2O———->2NaOH
Mgo + H2O———–>Mg(OH)2
The basic oxides react with acids to form salt and water.
Na2O+2HCl—————>2NaCl+H2 Fe2O3+3H2SO4—–>Fe2(SO4)3+3H2O - Neutral oxides:- Oxides which neither reacts with an acid nor with a base are called neutral oxides. A few non metal oxides are neutral oxides.
Eg:- N2O —>nitrous oxide
CO —–> carbon oxide
NO —-> Nitric oxide - Amphoteric oxides:- oxides which react with both acid, as well as base are called amphoteric oxides. A few metals are amphoteric oxides in nature.
SnO+2HCl—————->SnCl2+H2O
SnO+2NaOH———>Na2SnO2+H2O
Sodium stannite
PbO+HCl—————>PbCl2+H2O
PbO+2NaOH——–>NaPbO2+H2O
Sodium plumbite - Mixed or compound oxides:- Mixed oxides are made by combination of more than one simple oxides of the same element.
Ferrosoferric oxide,FeO4(FeO+Fe2O3)
Red lead, Pb3O4(2PbO+PbO2)
Manganomanganic oxide, Mn3O4.
They react with acids to give mixtures of salt Fe3O4+8Cl——->FeCl2+2FeCl3+4H2O
- Peroxide:- They contain peroxide linkage (-o-o-) and oxygen has -1 oxidation state. They react with dilute acid to give H2O2. Eg:- Na2O2, BaO2, H2O2, etc.
Na2O2+2HCl————>2Nacl+H2O2
BaO2+2HCl ————-> BaCl2+H2O2
