Have you ever noticed that hot dogs are sold in packages of 10, while the buns come in packages of eight? In this scenario, the buns are the limiting reactant in the sense that they limit the hot dog preparation to eight. The limiting reactant or reagent is the one that is consumed first in the chemical reaction, and its consumption halts the progress of the forward reaction.
Molar mass | (28.02) | (2.02) | (17.04) |
---|---|---|---|
Balanced equation | N2 + | 3H2 | 2NH3 |
No. of moles | |||
Amount |
Suppose you have a total of 25.0 kg of nitrogen to react with a total of 5.00 kg of hydrogen. What mass of ammonia can be produced? Which reactant is the limiting reactant? What is the mass of the reactant that’s in excess? Insert the masses in the correct rows and find the number of moles of both.
Molar mass | (28.02) | (2.02) | (17.04) |
---|---|---|---|
Balanced equation | N2 + | 3H2 | 2NH3 |
No. of moles | 892 mol | 2475 mol | |
Amount | 25,000 g | 5000 g |
Molar mass | (14.02) | (2.02) | (17.04) |
---|---|---|---|
Balanced equation | N2 + | 3H2 | 2NH3 |
No. of moles | 825 mol used | 2475 mol used | therefore 1650 mol produced |
Amount | 892 mol 23,117 g used 25,000g | 5000 g | 1650 mol (17.04) = 28,116 g produced |