# When a solution is diluted, does it change the number of moles dissolved?

$\text{Concentration"="Moles of solute"/"Volume of solution}$, and thus we express $\text{concentration}$ with units of $m o l \cdot {L}^{-} 1$. Upon dilution, i.e. the addition of more SOLVENT, we reduce the concentration (i.e. we make the quotient SMALLER by increasing the denominator), but the moles of solute is necessarily unchanged. Capisce?