calculez moli Mg, stiind M,Mg= 24g/mol
niu=m/M= 48/24=> 2mol Mg
din ecuatia chimica, deduc moli si masa HCl si moli MgCl2:
1mol.... ......2mol...............1mol
Mg + 2HCl----> MgCl2 + H2
2mol......x=4mol................y= 2mol
a .m,HCl=niuxM= 4x36,5g=...........................calculeaza
b. 2mol MgCl2