stoichiometry example problems with answers

Nitrogen in ammonia is sp3 hybridized but the ammonia molecule has trigonal pyramid geometry. Give reason

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Ans. In NH3 molecule, the central atom of nitrogen has three unpaired electrons in the ground state. The nitrogen atom then undergoes sp3 hybridization and forms four sp3 hybrid orbitals. The three sp3 hybrid orbitals overlap with three s orbitals of hydrogen atom while the fourth hybrid orbital contains lone pair of electrons and does … Read more

Molecular Propellers | Bsc | Msc Organic Chemistry

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Molecular propellers are a kind of atropisomerism involving substances. They are called molecular propellers because of their analogy with the propellers of airplanes or boats. Molecules of this type consist of two or more subunits. They may be single atoms or a combination of atoms. The term molecular propeller is not confined to cases where … Read more

Allenes Chemistry And Stereochemistry – 1

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The Molecule with no chiral center but chiral are called allenes, cumulenes with even no of double bonds. Biphenyls and similar compounds in which chirality is due to the restricted rotation of single bonds. Allenes, alkylidenes cycloalkanes, biphenyls, and so on are said to possess a chiral axis if we stretch a tetrahedron along its … Read more

Nuclear Over Houser Effect ( NOE)

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Discovered by – Albert Overhouser 1953 It is defined as the change in the intensity of one spin when the transition of another nucleus is perturbed from the equilibrium population. Nuclear spin that is coupled – gives rise to nuclear over houser effect. Through space, the coupling is also called dipolar coupling. It depends on … Read more

Periodic Table | Properties | Terms

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s & p – block elements are also called representative elements f – block elements – Lanthanides and actinides d block – transistion elements Typical elements – Li to F Transuranic elements – Artificial elements ( At. no > 93 (Np) Group VA / 15 – Nitrogen family – Pnicogenes – suffocating agents Group VA … Read more

Facts in Periodic Table

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Lightest metal – Li Lightest gas – H Metalloid – Ga , In , Ge , As , Sb. Liquid radioactive element – Francium Liquid non metal – Br2 Solid non metal – B , C , Si , P , S , I . Non metal sublimate – I2 Gaseous non metal – N … Read more

Finding the oxidation number of atom.

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Q. Calculate the oxidation number of Sulphur in K2S2O3 and SOCl2. Let the oxidation number of S in K2S2O3 be x. also, we know that the oxidation number of potassium is +1 and the oxidation number of oxygen is -2. Applying the rule, (+1) × 2 + (x) × 2 + (-2) × 3 = … Read more

What volume of CO2 will be delivered at NTP to extinguish the fire from a cylinder of 10 L? ( It contains 5Kg CO2 gas )

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Here, mass of CO2 = 5kg = 5 × 1000 = 5000 g Also we know that At STP , 44 g of CO2 will produce 22.4 L of CO2 gas. 5000g of CO2 will produce (22.4 × 5000 ) / 44 L of CO2 gas = 2545.45 L The volume of CO2 that will … Read more

Williamson’s Ether Synthesis | Organic Chemistry |

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Alcohol in reaction with active metal sodium gives sodium alkoxide. sodium alkoxide on reaction with an alkyl halide gives ether. It is known as Williamson’s ether synthesis helps to synthesize aliphatic, aromatic, symmetrical, unsymmetrical ethers. ROH + Na         =                    RONa + ½ H2 RONa + R – X      =                R – O – R + NaX RONa … Read more