Non-stoichiometric cuprous oxide, `Cu_(2)O` can be prepared in laboratory. In this oxide, copper to oxygen ratio is slightly less than 2:1. Can you account for the fact that this substance is a p-type semiconductor?

The metal which can form an oxide having metal: oxygen ratio 2:3 is

Copper forms two oxide Cu_(2)O_(x) and Cu_(2)O_(y) . For the same amount of metal,twice as much oxygen was used to form first oxide than to second oxide. What is the ratio of X and Y?

A non-stoichiometric compound Cu_(1.8)S is formed due to incorporation of Cu^(2+) ions in the lattice of cuprous sulphide. What percentage of Cu^(2+) ions the total copper centent is present in the compound

The oxidation number of an element in a compound decides its nature to acts as oxidant or reductant. Oxidation number is defined and the residual charge which an atom has or appears to have in a molecule whenal other atoms are removed from the molecule as ions. Oxidation number is frequently used interchangebly with oxidation state. The stock notations of oxidation number are based on the periodic property-electronegativity. An atom in a molecule can be assigned positive, negative or zero oxidation number by considering its environment. In few cases, oxidation number can evenn be fractional. Oxidation number of Y in YBa_(2)Cu_(2)O_(7) is +3, then oxidation number of Cu is:

The oxidation number of an element in a compound decides its nature to acts as oxidant or reductant. Oxidation number is defined and the residual charge which an atom has or appears to have in a molecule whenal other atoms are removed from the molecule as ions. Oxidation number is frequently used interchangebly with oxidation state. The stock notations of oxidation number are based on the periodic property-electronegativity. An atom in a molecule can be assigned positive, negative or zero oxidation number by considering its environment. In few cases, oxidation number can evenn be fractional. Oxidation number of oxygen in K_(2)O, K_(2)O_(2),KO_(2),KO_(3) are in the order:

Hydrogen bonding is said to be formed, -when sightly acidic hydrogen-atom attached to a strongly, electronegative fluorine, oxygen or nitrogen atom. is held with weak. electrostatic forces by the non-bonded pair of electrons of another atom. The co-ordination number of hydrogen in such cases is two. It acts as a bridge between two atoms, to one of which it is covalently bonded and to other attached through electrostatic forces, also called hydrogen bond. Though the hydrogen atoms in a methyl group are not polarised, if an electronegative group like chloro, carbonyl, nitro or cyano (in order to increase electronegativity) is attached to it, the C-H bond gets polarised due to the inductive effect and the hydrogen atom becomes slightly acidic resulting in the formation of weak hydrogen bonds. Though a weak bond the H-bond effects is large number of the physical properties of compounds some of which are - Boiling points of liquids - Solubility of polar compounds in polar solvents (containig H attached with strong electronegative atom) - Viscosity of liquids . Acidity Which of the following combinations can involve hydrogen bonding I) Mixture of KF and HF " " II) Mixture of CH_(3)COCH_(3) and CHCI_(3) III) Mixture of NH_(4) CI and H_(2)O" " IV) Mixture of CH_(3) and H_(2)O

Passage-III : The binary compounds of oxygen with other elements are called oxides. They are classified either depending upon their acid - base characteristics or on the basis of oxygen content. a ) Normal oxides : These oxides which contain oxygen atoms as permitted by the normal oxidation number, i.e., -2. Normal oxide may be acidic, basic, amphoteric or neutral. b) Polyoxides : The oxides which contain oxygen atoms different than those permitted by the normal oxidation number of -2. i) Peroxides : Two oxygen atoms are linked to each other and oxygen has -I oxidation number. They contain (O-O)^(2) unit. ii) Superoxides : These oxides contain (O-O)^(-1) units, i.e., each O-atom has oxidation number -1//2 . c ) Suboxides : These contain low content of oxygen than expected. d) Mixed oxides : These oxides are made of two simpler oxides. Which of the following pairs contains neutral oxides ?

Passage-III : The binary compounds of oxygen with other elements are called oxides. They are classified either depending upon their acid - base characteristics or on the basis of oxygen content. a ) Normal oxides : These oxides which contain oxygen atoms as permitted by the normal oxidation number, i.e., -2. Normal oxide may be acidic, basic, amphoteric or neutral. b) Polyoxides : The oxides which contain oxygen atoms different than those permitted by the normal oxidation number of -2. i) Peroxides : Two oxygen atoms are linked to each other and oxygen has -I oxidation number. They contain (O-O)^(2) unit. ii) Superoxides : These oxides contain (O-O)^(-1) units, i.e., each O-atom has oxidation number -1//2 . c ) Suboxides : These contain low content of oxygen than expected. d) Mixed oxides : These oxides are made of two simpler oxides. Which of the following pairs contains mixed oxides?

Passage-III : The binary compounds of oxygen with other elements are called oxides. They are classified either depending upon their acid - base characteristics or on the basis of oxygen content. a ) Normal oxides : These oxides which contain oxygen atoms as permitted by the normal oxidation number, i.e., -2. Normal oxide may be acidic, basic, amphoteric or neutral. b) Polyoxides : The oxides which contain oxygen atoms different than those permitted by the normal oxidation number of -2. i) Peroxides : Two oxygen atoms are linked to each other and oxygen has -I oxidation number. They contain (O-O)^(2) unit. ii) Superoxides : These oxides contain (O-O)^(-1) units, i.e., each O-atom has oxidation number -1//2 . c ) Suboxides : These contain low content of oxygen than expected. d) Mixed oxides : These oxides are made of two simpler oxides. Which of the following oxides is paramagnetic in nature?

Passage-III : The binary compounds of oxygen with other elements are called oxides. They are classified either depending upon their acid - base characteristics or on the basis of oxygen content. a ) Normal oxides : These oxides which contain oxygen atoms as permitted by the normal oxidation number, i.e., -2. Normal oxide may be acidic, basic, amphoteric or neutral. b) Polyoxides : The oxides which contain oxygen atoms different than those permitted by the normal oxidation number of -2. i) Peroxides : Two oxygen atoms are linked to each other and oxygen has -I oxidation number. They contain (O-O)^(2) unit. ii) Superoxides : These oxides contain (O-O)^(-1) units, i.e., each O-atom has oxidation number -1//2 . c ) Suboxides : These contain low content of oxygen than expected. d) Mixed oxides : These oxides are made of two simpler oxides. Which pair of species is referred to as suboxides?