Question

Ce masa de solutie HCl de concentratie 36.5% reactioneaza cu o bucata de 10g Zn de puritate 65%. Ce masa de ZnCl2 se obtine si ce volum de H2 se degaja? Azn=65 Ah=1 Acl=35.5 1 mol=22.4l

Answer 1

100% ...................... 10 g Zn impur

65% ....................... m = 65x10/100 = 6,5 g Zn

6,5 g   md g        m g      V L

 Zn  +  2HCl --> ZnCl2 + H2

  65     2x36,5     136       22,4

=> md = 6,5x2x36,5/65

= 7,3 g HCl

stim ca c% = mdx100/ms

=> ms = mdx100/c%

= 7,3x100/36,5 = 20 g sol HCl

=> m = 6,5x136/65 = 13,6 g ZnCl2

=> V = 6,5x22,4/65

= 2,24 L H2