# How many liters of Br_2 are in a container at STP that contains 2.25 moles of Br_2?

Jan 25, 2016

Approx. $100$ $m L$ . Why?

#### Explanation:

We need to know the density of elemental bromine. $\rho$ $=$ $3.11$ $g \cdot m {L}^{-} 1$ at STP.

Now there are $2.25$ $m o l$ of stuff; i.e. there are $2.25$ $\cancel{m o l}$ $\times$ $2 \times 79.90$ $g \cdot \cancel{m o {l}^{-} 1}$ $=$ $359.55$ $g$. (Note that I mulitplied by 2 in order to account for the molecularity of elemental bromine; it is $79.9$ $g \cdot m o {l}^{-} 1$ for the bromine ATOM!)

Using the density, $\rho$, this is $\frac{359.55 \cdot \cancel{g}}{3.11 \cdot \cancel{g} \cdot m {L}^{-} 1}$ $\cong$ $100$ $m L$ $=$ ??L

There are few things in the laboratory that are as corrosive as bromine; it can cause horrendous burns, and this quantity would be treated with respect.