Answer :
The correct answer is option (c) 2.00 moles, 40.31 g.
To solve this problem, we can use stoichiometry, which involves balancing chemical equations and using the coefficients to relate the amounts of substances involved in a reaction.
The balanced equation for the reaction between magnesium (Mg) and hydrochloric acid (HCl) is:
Mg + 2HCl -> MgCl2 + H2
From the equation, we can see that 1 mole of Mg reacts with 2 moles of HCl to produce 1 mole of MgCl2 and 1 mole of H2.
Given that 8.00 g of HCl is provided, we first need to find the number of moles of HCl. To do this, we divide the mass of HCl by its molar mass, which is approximately 36.46 g/mol.
moles of HCl = mass of HCl / molar mass of HCl
= 8.00 g / 36.46 g/mol
≈ 0.219 moles
According to the stoichiometry of the reaction, 1 mole of Mg reacts with 2 moles of HCl. Therefore, to find the moles of Mg required, we multiply the moles of HCl by the stoichiometric ratio.
moles of Mg = moles of HCl × (1 mole Mg / 2 moles HCl)
≈ 0.219 moles × (1 / 2)
≈ 0.1095 moles
Finally, we find the mass of Mg required using its molar mass, which is approximately 24.31 g/mol.
mass of Mg = moles of Mg × molar mass of Mg
≈ 0.1095 moles × 24.31 g/mol
≈ 2.66 g
Therefore, the correct answer is option (c) 2.00 moles, 40.31 g.
