# Question 78d25

Jun 30, 2017

Here's what you could do here.

#### Explanation:

The tricky thing to remember about gases is that their volume depends on the conditions for pressure and temperature.

In other words, the mass of carbon monoxide that occupies $\text{134 L}$ under certain conditions for temperature and pressure will occupy a different volume under different conditions for temperature and pressure.

Since you didn't provide any information about the temperature and the pressure at which the sample is kept, I'll assume that you're working at STP conditions.

Now, STP conditions are defined as a pressure of $\text{100 kPa}$ and a temperature of ${0}^{\circ} \text{C}$. Under these conditions, $1$ mole of any ideal gas occupies $\text{22.71 L}$.

"1 mole of an ideal gas" color(white)(aaaa) stackrel(color(white)(acolor(blue)("at STP")aaa))(->) color(white)(underbrace(color(black)("22.7 L"))_ (color(red)("molar volume of a gas at STP"))

So, use the molar volume of a gas at STP to calculate the number of moles of carbon monoxide present in your sample

134 color(red)(cancel(color(black)("L"))) * "1 mole CO"/(22.7color(red)(cancel(color(black)("L")))) = "5.903 moles CO"#

To convert this to grams, use the molar mass of carbon monoxide

$5.903 \textcolor{red}{\cancel{\textcolor{b l a c k}{\text{moles CO"))) * "28.01 g"/(1color(red)(cancel(color(black)("mole CO")))) = color(darkgreen)(ul(color(black)("165 g}}}}$

The answer is rounded to three sig figs, the number of sig figs you have for the volume of the sample.