Question

EEN 211 Home work #2 Due Date: 03/23/2020 1. The equilibrium fraction of lattice sites that are vacant in silver (Ag) at 700C is 2 x 10-6 Calculate the number of vacancies (per meter cubed) at 700 C. Assume a density of 10.35 g/cm for Ag 2. What is the composition, in atom percent of an alloy that consists of 92.5 wt% Ag and 7.5 wrCu? 3. Calculate the number of vacancies per cubic meter at 1000°C for a metal that has an energy for vacancy formation of 1.22 eVlatom, a density of 6.25 g/cm3, and an atomic weight of 37.4 g/mol. 4. The activation energy for the diffusion of copper in silver is 193,000 J/mol Calculate the diffusion coefficient at /200 K (927°C), given that Dar 1000 K (727°C) is 10 x 10 w/s. 5. (a) Calculate the diffusion coefficient for magnesium in aluminum ar 450°C (b) What time will be required at 550°C to produce the same diffusion result in terms of concentration at a specific point) as for 15 h at 450°C?

can you answer these for me! I am struggling.

Answer 1

riven data Density of Ag = 10:35 g/cm3 Temperature - 700°C . We know that, N= NA PAG Ang tay NA is Avogadro numben. Pag is dersity of silues. Anges molar mass of silles. = 6:023 x1033) (10.359/cm3) 10719 g/moj = $177x13 atomslcm3 Number of vacant atums = fraction x total no. of Sites Nv=COXN = 2106x5,77X1022 2 ):15 xidmatoms loma 2015</atomslam) (10%atom, ? latom, com NV = 15x10°3 atom slma3