# How many hydroxide ions are needed to completely neutralize 1.0 liter of 0.50 M HCI?

May 21, 2018

$\text{Half an Avocado number....}$
$H C l \left(a q\right) + N a O H \left(a q\right) \rightarrow N a C l \left(a q\right) + {H}_{2} O \left(l\right)$
We have $1.0 \cdot L \times 0.50 \cdot m o l \cdot {L}^{-} 1 \equiv 0.50 \cdot m o l$ with respect to (formal!) hydrogen chloride molecules. Stoichiolmetric equivalence requires an equal number of hydroxides....i.e. $\frac{1}{2} \cdot m o l \times {\underbrace{6.022 \times {10}^{23} \cdot m o {l}^{-} 1}}_{\text{Avogadro's number}}$ . Claro?