Final answer:
In a limiting reactant problem, you determine which reactant will be completely consumed and which reactant will be in excess. The limiting reactant is the one that is consumed first and determines the amount of product that can be formed. The mass of the leftover reactant can be calculated by subtracting the amount of reactant consumed from the initial amount.
Step-by-step explanation:
In a limiting reactant problem, you need to determine which reactant will be completely consumed and which reactant will be in excess. The limiting reactant is the one that is consumed first and determines the amount of product that can be formed. To find the limiting reactant, you can compare the initial amounts of the reactants and calculate the moles of each reactant. The reactant that produces fewer moles of product is the limiting reactant.
After determining the limiting reactant, you can calculate the mass of the leftover reactant by subtracting the amount of reactant consumed from the initial amount. This can be done by multiplying the moles of the limiting reactant by the molar mass of the leftover reactant.
For example, if you have 10 grams of reactant A and 20 grams of reactant B, and the balanced equation shows that the reaction requires 2 moles of reactant A and 3 moles of reactant B to form the product, you would calculate the moles of each reactant using their molar masses.
If reactant A produces 1 mole of product and reactant B produces 2 moles of product, reactant A would be the limiting reactant since it produces fewer moles of product. To find the mass of the leftover reactant, you can subtract the moles of reactant A used in the reaction from the initial amount of reactant A and convert the result to grams using its molar mass.