Question

12g Mg (at mass 24) react with dilute mineral acid to produce max hydrogen equal to? (Ans= 0.5mol) but how??

Answer 1

Since the dilute mineral acid is not given, we will use the hydrogen ions:

Equation:

Mg + 2H^+ ----->  Mg (ions)  + H2
(s)     (aq)            (s/aq)          (g)

ratio of moles of Mg: H2 =  1:1

moles of magnesium ions:  moles= mass/molar mass
                                                      12/24  =0.5 moles

if ratio = 1:1 then moles of hydrogen gas produced = 0.5 moles

The question requires amount of hydrogen gas:
Mass= moles x molar mass
        = 0.5 x 2  =1 g
Therefore 1 g of hydrogen gas is produced.

Answer 2

Answer:

0.5 mol

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