# Question #6b45c

Jan 27, 2017

The mass of the sample of nitrogen gas at STP is $\text{1.9 g}$.

#### Explanation:

In order to determine the mass of 1.5 L of nitrogen gas at STP, you will need to know its density at STP. You will then have volume and density. You can then use the density equation to determine the mass of the sample of nitrogen gas at STP.

The density of nitrogen gas, $\text{N"_2}$, at STP is $\text{1.25 g/L}$.
http://nobel.scas.bcit.ca/chem0010/unit7/mole8.htm

The density equation is written below.

$\textcolor{red}{\text{density"="mass"/"volume}}$

In order to use the density equation to solve for mass, you will need to rearrange the equation to isolate mass.

$\textcolor{red}{\text{mass"="density"xx"volume}}$

To determine the mass of $\text{N"_2}$ at STP, multiply the density by the volume.

$\text{mass of nitrogen gas at STP" =(1.25"g"/cancel"L")xx(1.5cancel"L")="1.9 g}$ rounded to two significant figures