化学比赛演习题(国外英文资料).docVIP

化学竞赛练习题(国外英文资料)The seventh section?? selected exercises? 1. diatomic compound A is composed of two elements of 10 or less, the intramolecular both sigma bond and pi bond, and coordination bond. The chemical formulas for A are:, -, -, -, -,... The molecules of 2.HNO2 have two isomers, and their structural forms are:, -, -, -, -, -, -, -... 3.NSF is an unstable compound that can be polymerized into trimer molecules, A. Write the structure of the A. 4. the crystal cell of the known SrCl2 crystal is shown on the right. In the figure, said Sr2 +, they are in large angle and face centered cube; indicates that Cl ions, they are in a large cube body diagonal, or small cubic dotted connection for top corner. Ask: (L) what is the coordination number of Sr2 + and Cl? ? (2) if the cell volume is v? Cm3, 1mol? SrCl2 cm3, volume V? Is the Avogadro constant NA? The following 5. calculation? Crystal space utilization rate (the percentage of atomic volume of crystal space)? (1) copper (cubic close packed)? (2) (tungsten BCC lattice)? (3), the diamond crystal as a cube. In the 8 corners of the cube and the top 6 heart of each of the 1 C atoms with 4 C atoms in the cube, the 4 C atoms is this: will the cube into 8 smaller cubes, numbered the 1 carbon atoms located in the center of the front right angle small cube. Grade 2 C atoms in the left small cube center, center of grade 3 C atoms in the small cube located right after the 4 grade C atoms located on the front in the center of the small cube. 6.? The theory that high temperature NaCl crystal conduction is due to Na + migration to another vacancy caused by (shown at right), the Na + through a consists of 3 Cl - ions (Cl - ion minimum triangle window does not contact each other). Known as a/2==282pm, R (Cl -), ==167pm, R (Na +), ==116pm. Calculate the radius of the triangle window. What about the structure of the 7. blue molecule, as shown on the right, then there are two chlorine substitutes. ?? 8. in an organic solvent to n Moore M