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The FBISE was established under the FBISE Act 1975. [2] It is an autonomous body of working under the Ministry of Federal Education and Professional Training. [3] The official website of FBISE was launched on June 7, 2001, and was inaugurated by Mrs. Zobaida Jalal, the Minister for Education [4] The first-ever online result of FBISE was announced on 18 August 2001. [5]
Tin(IV) chloride is well known as a Lewis acid. Thus it forms hydrates. The pentahydrate SnCl 4 ·5H 2 O was formerly known as butter of tin. These hydrates consist of cis-[SnCl 4 (H 2 O) 2] molecules together with varying amounts of water of crystallization. The additional water molecules link together the molecules of [SnCl 4 (H 2 O) 2 ...
Salts form upon evaporation of their solutions. [9] Once the solution is supersaturated and the solid compound nucleates. [9] This process occurs widely in nature and is the means of formation of the evaporite minerals. [10] Insoluble salts can be precipitated by mixing two solutions, one with the cation and one with the anion in it.
This same basic structure is found in many other compounds and is commonly known as the NaCl structure or rock salt crystal structure. It can be represented as a face-centered cubic (fcc) lattice with a two-atom basis or as two interpenetrating face centered cubic lattices. The first atom is located at each lattice point, and the second atom is ...
Ball-and-stick model of the tetrahydroborate anion, [BH 4] −. Borohydride refers to the anion [B H 4] −, which is also called tetrahydridoborate, and its salts. [1] Borohydride or hydroborate is also the term used for compounds containing [BH 4−n X n] −, where n is an integer from 0 to 3, for example cyanoborohydride or cyanotrihydroborate [BH 3 (CN)] − and triethylborohydride or ...
Dilute solutions are subject to hydrolysis, yielding an insoluble basic salt: SnCl 2 + H 2 O ⇌ Sn(OH)Cl + HCl. Hydrolysis is prevented in the presence of hydrochloric acid, typically of the same or greater molarity as the stannous chloride. Solutions of SnCl 2 are also unstable towards oxidation by the air: 6 SnCl 2 + O 2 + 2 H 2 O → 2 SnCl ...
Typically, a solution of PbI 2 in an organic solvent, such as dimethylformamide or dimethylsulfoxide, is applied over a titanium dioxide layer by spin coating. The layer is then treated with a solution of methylammonium iodide CH 3 NH 3 I and annealed, turning it into the double salt methylammonium lead iodide CH 3 NH 3 PbI 3, with a perovskite ...
A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): BH 3 ·O(CH 2) 4 or diethyl ether: BH 3 ·O(CH 3 CH 2) 2. Many Lewis acids and Lewis bases reacting in the gas phase or in non-aqueous solvents to form adducts have been examined in the ECW model . [ 3 ]