C=md/ms*100=>md=C*ms/100=20*100/100=20g HCl
Fe + 2HCl -> FeCl2 + H2
a) MHCl=36,5g/mol
2*36,5g HCl.........................2g H2
20g HCl.................................xg H2
x=2*20/73=0,54794 g H2
n=m/M=0,54794/2=0,2739 moli H2
b) MZn=65g/mol
65g Zn.....................2*36,5g HCl
xg................................20g HCl
x=65*20/73=17,8g Zn
n=m/M=17,8/65=0,2739 moli Zn