Consider the following generic reaction: $$ \mathrm{Y}_{2}+2 \mathrm{XY} \longrightarrow 2 \mathrm{XY}_{2} $$ In a limiting reactant problem, a certain quantity of each reactant is given and you are usually asked to calculate the mass of product formed. If \(10.0 \mathrm{~g}\) of \(\mathrm{Y}_{2}\) is reacted with \(10.0 \mathrm{~g}\) of \(\mathrm{XY}\), outline two methods you could use to determine which reactant is limiting (runs out first) and thus determines the mass of product formed. A method sometimes used to solve limiting reactant problems is to assume each reactant is limiting and then calculate the mass of product formed from each given quantity of reactant. How does this method work in determining which reactant is limiting?

There are two methods to determine the limiting reactant: Method 1: Determine the moles of each reactant and compare their mole ratios: 1. Moles of Y2 = Mass of Y2 / MY2 2. Moles of XY = Mass of XY / MXY 3. Compare the ratios (Y2 moles)/1 : (XY moles)/2. The reactant with the smaller amount in the comparison is the limiting reactant. Method 2: Calculate the theoretical product mass from each reactant: 1. Assume each reactant is limiting separately and calculate the mass of XY2 formed for each. 2. Compare the masses of XY2 formed in both scenarios: XY2 mass from Y2 : XY2 mass from XY. The scenario with a smaller amount of product is the correct one, and the limiting reactant determines the maximum amount of product that can be formed in a reaction. The method that assumes each reactant is limiting is effective in determining the limiting reactant, as it allows us to identify the limiting reactant based on the outcome of the product formation.