Question

+-/8.37 points MCM8 8.P.022 12. In heterogeneous catalysis the rate of the catalyzed reaction, khs depends on the contact surface area between the reactants in one phase and the catalyst in another Suppose you have a block of platinum measuring 2.49 cm x 2.58 cm x 3.10 cm. Platinum has a density of 21.45 q/cm3 (a) What is the total surface area, i.e. the area in possible contact with the reactants, of this block of platinum? 4.0 cm2 (b) What is the volume of the block? 4.0 cm3 (c) What is the mass of the block? 4.0 (d) What is the accessible surface area per unit of mass? cm2/g 4.0 Metal catalysts are often added to a reaction powdered or adsorbed too a carrier, such as graphite or silica, to increase their contact surface area Suppose you figure out a process that whittles the block of platinum down to a homogeneous collection of spheres with a diameter of 316 nm. (e) What is the surface area of one such sphere? 4.0 cm2 (f) What is the mass of one such sphere? 4.0 (q) Assuming you have the exact same mass of spheres as the block you started with, how many spheres do you have? 4.0 spheres (h) What is the total surface area, i.e. the area in possible contact with the reactants, of this batch of platinum spheres? 4.0 cm2 (i) What is the accessible surface area per unit of mass? cm2/g 4.0 (j) What is the approximate fold-increase in reaction rate that can be obtained by using these spheres instead of the block of platinum? 4.0 -fold Submit Answer Practice Another Version

Answer 1

Block of Plat nium measuring 2.49 cm x 2.58 cm x 3.10cm density of Platnium 21.45 g cm - 1 Total surface area= 2 ( 16 tbh the) where e= length of box b= breadth of box h= height of box so to tell surface aree = & ( 2:49 x 2.58 + 8:58 X3.10 + 3.10X 2.49) = 2 (6.4242 + 7.998 + 7.719) = 44.28 cm? Total surface area = 44.28 cm b) volume block = exbxh 2.49 cm x 2.58cm x 3.10 cm 19.92 cm3 9) Man - density x volume = 21.45 g x 19.92 como = 472.39 surface area surface area per unit mans = Accesible mas & 44.28 cm = 0.094 cm2 19 472-3 g