Please, I really need your help to solve these questions. Thanks for considering my request. Especially for #4-b.

1. Consider the cubic unit cell of Cu20 (a - 4.27 ): Assign the red and blue ions as Cut or O?. Draw the unit cell with a red ion at the origin. How would you describe this crystal structure in terms of (a) a lattice plus basis, (b) interpenetrating Bravais lattices, and (c) a close-packed array with interstitial sites filled? Draw a projection of the shifted unit cell onto the b-c face. What is the shortest Cu-Cu distance? Does the crystal have an inversion center? 2. An ammonium halide, NH4X, has the CsCl structure at room temperature, a = 4.059 A, and transforms to the NaCl structure above 140 C, a = 6.867 A. (a) The density of the room temperature polymorph is 2.431 g cm. Identify the substance. (b) Calculate the values of the six largest d-spacings for this polymorph. (c) Calculate the percentage difference in molar volume between the two polymorphs, ignoring thermal expansion effects. (d) Assuming an effective radius of 1.50 for the spherical NH4 ion and that anions and cations are in contact, calculate the radius of the anion in each structure. Are the anions in contact in the two structures? 4) a) Why is it important to understand the kinetics of chloride ligand loss to make the platinum aquo species in Cisplatin (1)? b) If analogues could be made that reduces ligand loss, how would this make it a more effective drug