Answer:
The maximum mass of phosphoric acid that can be formed is 34.2 g
The molecular formula of the limiting reagent is P₄O₁₀
The mass of the excess reagent (water) that remains after the reaction is complete is 3.76 g
Explanation:
Hi there!
Let´s write the balanced chemical equation:
P₄O₁₀ + 6 H₂O → 4 H₃PO₄
The molar masses of the reactants and the product are the following:
P₄O₁₀ = 284 g
H₂O = 16 g
H₃PO₄ = 98 g
The number of moles of the reactants we have are the following:
24.8 g P₄O₁₀ · 1 mol/ 284 g = 0.0873 mol P₄O₁₀
13.2 g H₂O · 1 mol/ 18 g = 0.733 mol H₂O
We know from the chemical equation that 1 mol of P₄O₁₀ reacts with 6 mol of H₂O, then, 0.0873 mol P₄O₁₀ will react with:
0.0873 mol P₄O₁₀ · 6 mol H₂O/ 1 mol P₄O₁₀ = 0.524 mol H₂O
Then, water is in excess because we have 0.733 mol and only 0.524 mol will react. Thus, the limiting reagent is P₄O₁₀
The number of moles of water that will remain after the reaction is complete is the following:
0.733 mol - 0.524 mol = 0.209 mol
Let´s convert that amount of water into mass units
0.209 mol · 18 g / mol = 3.76 g
3.76 g of water remains after the reaction is complete.
Assuming that the reaction has a yield of 100% since 1 mol of P₄O₁₀ produces 4 mol of phosphoric acid, 0.0873 mol P₄O₁₀ will produce
( 0.0873 mol P₄O₁₀ · 4 mol H₃PO₄/ mol P₄O₁₀ ) 0.349 mol phosphoric acid.
Then, the maximum mass of phosphoric acid that can be formed is the following:
0.349 mol H₃PO₄ · 98 g / 1 mol = 34.2 g
