You must first balance the chemical equation to determine the limiting reagent

Question

True or false? Please help

Answer 1

True. Stoichiometry is very important when determining limiting reagents. For example, when making water, we combine Hydrogen and Oxygen:

H₂ + O₂ --> H₂O

Unless I balanced the equation, I wouldn't be able to tell how much I needed of each component to make a molecule of water. The balanced equation shows that I need twice as many moles of Hydrogen as Oxygen in order to acheive the best yield.

2 H₂ + O₂ --> 2 H₂O

Now that I understand the mole ratio needed to fulfill this synthesis, we must look at the actual moles given. In this case, we can make up an amount:

1 mole of oxygen, and 1 mole of hydrogen

We can clearly see Hydrogen is the limiting reagent, because we would need 2 moles of Hydrogen to completely consume 1 mole of Oxygen.