Question

In 200g solutie HCl de concentratie , 36,5% se introduce magneziu . Ce cantitati de clorura de magneziu si hidrogen se obtin ?

Answer 1

2HCl+Mg=2MgCl=H2
C=md/ms *100
md=c*ms/100=36.5*200/100=73 g HCl
M molara HCl=1+35.5=36.5
Daca in 73 g de Hcl.........................x g de H
In 2*36.5 g de HCl............................2 g de H
x=73*2/2*36.5=2 g deH

Answer 2

md=ms*c/100=200*36,5/100=73 g HCl
2 HCl + Mg ---> MgCl2 + H2
2 * 36,5 g HCl.......24 g Mg........2 g H
73 g HCl................x g Mg..........y g H        
x = 24 g Mg si y = 2 g H
masa molara HCl = 1+35,5=36,5 g/mol