Question

$12\, g$ of $Mg$ (at. mass $=24$ ) will react completely with an acid to give :

• A. 1 mole of $H _{2}$
• B. $\frac{1}{2}$ mole of $H _{2}$
• C. 1 mole $O _{2}$
• D. None of these

Answer 1

Answer: (B)

$Mg +2 HCl \longrightarrow MgCl _{2}+ H _{2}$
$24\, g.\, Mg$ gives one mole $H _{2}$