# A mass of 55.9*g of magnesium metal is reacted with an equimolar quantity of hydrochloric acid; what molar quantities of product are generated?

$M g \left(s\right) + 2 H C l \left(a q\right) \rightarrow M g C {l}_{2} \left(a q\right) + {H}_{2} \left(g\right)$
And thus if you have EQUIMOLAR quantities of metal and acid as specified in the question, only half an equivalent of $M g C {l}_{2}$ and dihydrogen will be generated.
So you gets approx. $2.3 \cdot m o l$ each of magnesium chloride and dihydrogen gas.