When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) arrow MgCl2 (aq) + H2 (g), if 24.3 g of Mg and 75.0 g of HCl are allowed to react, calculate the mass of H2 that is produced.
1.00 g
2.00 g
4.00 g
5.00 g

Question

When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) arrow MgCl2 (aq) + H2 (g), if 24.3 g of Mg and 75.0 g of HCl are allowed to react, calculate the mass of H2 that is produced.    
       1.00 g
        2.00 g
        4.00 g
        5.00 g

anonymous · Answer

Find the number of moles that each weight corresponds to. You will get the same number of moles of H2 that you start with of Mg. Convert that number of moles into g.