Mg+2HCl------- MgCl2 +H2
2 moles ofHCl use 1 mole of Mg
3.91 mol of HCl=1/2 *3.91
Moles of Mg used = 1.955 moles
Moles of HCl used=3.91 mol
1 mole of Mg make 1 mole of MgCl2
So moles of MgCl2=1.955 moles
Molar mass=24+ (35.5*2)
Molar mass= 95 g/ mol
Mass of MgCl2 produced=moles *molar
