Answer:
0.98 g of H₂
Explanation:
the balanced equation for the reaction is
Mg + 2HCl ---> MgCl₂ + H₂
molar ratio of Mg to H₂ is 1:1
number of Mg moles reacted = 12 g/ 24.3 g/mol = 0.49 mol
according to molar ratio
when 1 mol of Mg reacts 1 mol of H₂ is formed
therefore when 0.49 mol of Mg reacts - 0.49 mol of H₂ forms
therefore mass of H₂ formed = 0.49 mol x 2 g/mol = 0.98 g
mass of H₂ formed is 0.98 g