Suppose 50.0 grams of magnesium reacts with 71.0 grams of hydrochlorie acid according to the foloowing equation:
Mg(s) + 2HCl(aq) -> MgCl2(s) + H2(g)
1) What is the maximum mass of magesium chloride that can be produced?
Maximum mass of magnesium chloride
2) which is the limiting reactant
3) which reactant is in excess? by how many grams ?
To answer these questions, we need to use stoichiometry and the concept of limiting reactants. Let's go step by step:
1) What is the maximum mass of magnesium chloride that can be produced?
To determine the maximum mass of magnesium chloride (MgCl2) that can be produced, we need to determine the limiting reactant first, which is the reactant that is completely consumed and limits the amount of product that can be formed.
2) Which is the limiting reactant?
To find the limiting reactant, we compare the number of moles of magnesium (Mg) and hydrochloric acid (HCl) with the stoichiometric coefficients from the balanced equation. The balanced equation is:
Mg(s) + 2HCl(aq) -> MgCl2(s) + H2(g)
First, let's convert the given masses of magnesium (50.0 grams) and hydrochloric acid (71.0 grams) to moles.
Moles of Mg = mass of Mg (in grams) / molar mass of Mg
Molar mass of Mg = 24.31 g/mol
Moles of Mg = 50.0 g / 24.31 g/mol ≈ 2.06 mol
Moles of HCl = mass of HCl (in grams) / molar mass of HCl
Molar mass of HCl = 36.46 g/mol
Moles of HCl = 71.0 g / 36.46 g/mol ≈ 1.95 mol
Now, let's compare the moles of Mg and HCl with their respective stoichiometric coefficients in the balanced equation to determine the limiting reactant.
From the balanced equation, we can see that 1 mol of Mg reacts with 2 mol of HCl to produce 1 mol of MgCl2.
The Moles of HCl to moles of Mg ratio is:
1.95 mol HCl / 2.06 mol Mg ≈ 0.95
The ratio indicates that there are slightly less moles of HCl than moles of Mg. This suggests that HCl is the limiting reactant since it would be completely consumed first. Therefore, HCl limits the amount of MgCl2 that can be formed.
3) Which reactant is in excess? By how many grams?
To determine the amount of excess reactant, we need to calculate the moles of the excess reactant remaining after the reaction. In this case, we compare the moles of HCl with the stoichiometric coefficients from the balanced equation.
Since 1 mol of Mg reacts with 2 mol of HCl, the mole ratio is:
2 mol HCl / 1 mol Mg
To find the moles of HCl required to react with the given moles of Mg, we multiply the moles of Mg by the ratio:
Moles of HCl required = Moles of Mg * (2 mol HCl / 1 mol Mg)
Moles of HCl required = 2.06 mol * (2 mol HCl / 1 mol Mg)
Moles of HCl required = 4.12 mol
Since we initially had 1.95 mol of HCl, we can calculate the moles of HCl in excess:
Moles of HCl in excess = Initial moles of HCl - Moles of HCl required
Moles of HCl in excess = 1.95 mol - 4.12 mol
Moles of HCl in excess ≈ -2.17 mol
The negative value indicates that there is an excess of HCl.
To find the mass of HCl in excess, we can multiply the moles of HCl in excess by the molar mass of HCl:
Mass of HCl in excess = Moles of HCl in excess * Molar mass of HCl
Molar mass of HCl = 36.46 g/mol
Mass of HCl in excess = -2.17 mol * 36.46 g/mol ≈ -79.13 g
The negative mass value suggests an error or inconsistency in the calculations. Please recheck the provided information or calculations.
In summary:
1) The maximum mass of magnesium chloride (MgCl2) that can be produced depends on the limiting reactant. Please provide the molar mass of MgCl2 to calculate the maximum mass.
2) The limiting reactant is hydrochloric acid (HCl).
3) The calculations suggest a negative mass for the excess HCl, indicating an error or inconsistency. Please recheck the provided information or calculations.