# How would you identify a limiting reagent in a chemical reaction?

Nov 8, 2015

Go through the mole!

#### Explanation:

When you are given the masses of the reactants, you need to convert them into moles.

For example:
$H C l + N a O H \to H 2 O + N a C l$

we have 2.3 grams of $H C l$ and 3.5 grams of $N a O H$.
First we must go through the mole

2.3 $g$ $H C l$ x 1 mole $H C l$ = 0.0630 mol $H C l$
36.46 $g$ $H C l$

3.5 $g$ $N a O H$ x 1 mole $N a O H$ = 0.0875 mol $N a O H$
40 $g$ $N a O H$

As you can see, there is less moles of $H C l$ than $N a O H$, therefore the $H C l$ will run out first, making it the limiting reagent.