1.97 ml.
Mg reacts with HCl at a 1:2 ratio.
Mg + 2 HCl → MgCl₂ + H₂.
How many moles of atoms in 0.0240 g of Mg?
The molar mass [tex]M[/tex] of Mg is 24.305 g/mol. In other words, the mass of one mole of Mg atoms is 24.305 gram.
[tex]n = \dfrac{m}{M} = \dfrac{0.0240}{24.305} = 9.87 \times 10^{-4} \; \text{mol}[/tex].
How many moles of HCl does it take to oxidize that [tex]9.87 \times 10^{-4} \; \text{mol}[/tex] of Mg?
It takes 2 moles of HCl to oxidize 1 mole of Mg. As a result, it takes [tex]2 \times 9.87 \times 10^{-4} = 1.97 \times 10^{-3}\; \text{mol}[/tex] to oxidize [tex]9.87 \times 10^{-4}\; \text{mol}[/tex] of Mg.
Mg is the limiting reactant, meaning that HCl is in excess. There needs to be more than [tex]1.97 \times 10^{-3}\; \text{mol}[/tex] HCl for Mg to be the limiting reactant.
How many liters of 1.00 M HCl?
1.00 M is the same as 1.00 moles per liter.
[tex]V = \dfrac{n}{c} = \dfrac{1.97 \times 10^{-3} \; \text{mol}}{1.00 \; \text{mol}\cdot \text{L}^{-1}} = 1.97 \times 10^{-3} \; \text{L} = 1.97 \; \text{mL}[/tex].
