Final answer:
To determine the limiting reactant between magnesium and hydrochloric acid, the moles of each reactant are calculated. Magnesium, with 0.00185 mol available, requires 0.0037 mol of HCl to fully react according to stoichiometry. Since there is excess HCl (0.09 mol), magnesium is the limiting reactant.
Step-by-step explanation:
Determining the Limiting Reactant
To find out which reactant is limiting between magnesium and hydrochloric acid (HCl), we need to calculate the moles of each reactant and then determine which one will be completely consumed first in the reaction. Using the molecular weight of magnesium, which is approximately 24.31 g/mol, we have:
0.045 g Mg × (1 mol Mg / 24.31 g Mg) = 0.00185 mol Mg
To calculate the moles of hydrochloric acid, the molarity and volume are used:
(6 mol HCl / 1 L) × (0.015 L) = 0.09 mol HCl
The balanced equation for the reaction between magnesium and hydrochloric acid is:
Mg + 2HCl → MgCl₂ + H₂
Based on the stoichiometry of the balanced equation, 1 mole of Mg reacts with 2 moles of HCl. Therefore, to react with 0.00185 mol of Mg, we would need 0.0037 mol of HCl. Since there is significantly more moles of HCl available (0.09 mol), magnesium is the limiting reactant.