How do I distinguish between the limiting reactant and excess reactant in a chemical equation?
YOu have to look at the balanced reaction, then see how many moles of each reactant you have. For instance
3A+ B >>>
and you have 4 moles of A , and 1.4 moles of B.
The balanced reaction requires if you have 1.4 moles of b, you should have 3*1.2=4.2 moles of A, and you don't have that. So A is limiting, you will run out of it. THe excess is B: how much excess? 4/3=1.33 moles of B needed, so excess is 1.4-1.33 moles.
To distinguish between the limiting reactant and excess reactant in a chemical equation, you need to follow these steps:
Step 1: Write and balance the chemical equation.
Start by writing the balanced chemical equation for the reaction. Make sure that the equation is balanced in terms of the number of atoms on each side.
Step 2: Determine the stoichiometric ratio.
Examine the coefficients in the balanced equation to determine the stoichiometric ratio between the reactants. This gives you the mole-to-mole ratio of the reactants.
Step 3: Convert grams to moles.
Convert the given quantities of reactants from grams to moles using their respective molar masses. This step allows you to compare the amounts of reactants on the same scale.
Step 4: Compare moles of reactants.
Compare the number of moles of each reactant using the ratio from Step 2. This comparison will help you identify which reactant will be completely consumed and which will be left in excess.
Step 5: Identify the limiting reactant.
The limiting reactant is the reactant that is completely consumed, limiting the amount of product that can be formed. It is the reactant with fewer moles than the stoichiometric ratio suggests.
Step 6: Calculate the amount of excess reactant.
Once you have identified the limiting reactant, you can calculate the amount of excess reactant remaining after the reaction by subtracting the amount of limiting reactant consumed from the initial amount of the excess reactant.
By following these steps, you can determine the limiting reactant and excess reactant in a chemical equation.