Question

Ce masa de zinc se gaseste in 12g ZnCO3?

Answer 1

$M_{ZnCO_3}=65+3(12+16)=65+3*28=65+84=149\ g/mol \\ 149\ g\ ZnCO_3............65\ g\ Zn \\ 12\ g\ ZnCO_3..................x\ g\ Zn \\ x=\frac{12*65}{149}=5,23 g\ Zn$