Answer to Question #30681 in Other Chemistry for Kel
How many grams of magnesium do you need to produce 285 grams of magnesium chloride.
Mg + 2HCl----> MgCl2 + H2
First of all we can find the amount of substance of magnesium chloride. We can use the formula n = m/M where n - the amount of substance m - the mass M - the molar mass, which is calculated: M(MgCl2) = Ar(Mg) + 2* (Cl) = 24 + 2*35.5 = 95g/mol n(MgCl2) = 285 g / 95 g/mol = 3 moles According the equation Mg + 2HCl--->MgCl2 + H2 we can find the amount of substance of magnesium: n(Mg) = n(MgCl2) = 3 moles So the mass will be: m(Mg) = n(Mg)*M(Mg) M(Mg) = 24 g/mol m(Mg) = 3 moles * 24 g/mol = 72 g