# What is the molar mass of K?

$\text{molar mass}$ $\left(\text{K}\right) = 39.1$ $\text{g}$ ${\text{mol}}^{-} 1$
The molar mass of a species is the mass of 1 mole of that substance in grams, and equates to its relative atomic mass; however, molar mass also requires the unit $\text{g}$ ${\text{mol}}^{-} 1$ to be appended. Thus:
$\text{molar mass}$ $\left(\text{K}\right) = 39.1$ $\text{g}$ ${\text{mol}}^{-} 1$