Question

Putin ajutor ? Urgent 7.2 cu tot cu rezolvare

Answer 1

20 g ....................... m g

2Ca  +  O2  =>  2CaO

2x40..................... 2x56

=> m = 20x2x56/2x40 = 28 g CaO

28 g ........................... a g

CaO  +  H2O  =>  Ca(OH)2

56...............................74

=> a = 74x28/56 = 37 g Ca(OH)2

n = nr moli = masa subst. / M.moleculara subst.

=> n = 37 / 74 = 0,5 moli Ca(OH)2