# How many moles of chlorine gas are associated with a 45*g mass of the element?

Sep 20, 2016

A bit over a $\frac{1}{2}$ mole of $C {l}_{2}$ gas.

#### Explanation:

All (well most) elemental gases are binuclear: i.e. ${O}_{2}$, ${N}_{2}$, ${H}_{2}$, ${F}_{2}$. The exceptions are the Noble Gases, which are unimolecular. In any case all the halogens (gas, liquid, and solid) are bimolecular, i.e. ${X}_{2}$.

$\text{Moles of stuff}$ $=$ $\text{Mass of stuff"/"Molar mass of stuff}$ $=$ $\frac{45.12 \cdot \cancel{g}}{70.9 \cdot \cancel{g} \cdot m o {l}^{-} 1}$

$=$ $> 0.6 \cdot m o l$ $C {l}_{2}$ gas.

Note that you simply have to know that chlorine, and fluorine gases, and liquid bromine and solid iodine are BIMOLECULAR.