The Concept Of Limiting Reagent
We will further explore this scenario through the following examples.
First, we have to convert the grams of the substances to moles. Then make the comparison to see which one is the limiting reagent. By now, you should be comfortable with the conversion of moles to grams and vice versa. The number of moles of magnesium present is 2.5 moles. According to the equation, 1 mole of magnesium reacts with 2 moles of hydrogen chloride. For magnesium to completely react, there should be at least 5 moles of hydrogen chloride present. If you calculate the number of moles of hydrogen chloride present, you will get 4 moles. This amount of hydrogen chloride is not enough to completely react with the amount of magnesium present. So the limiting reagent is hydrogen chloride.