# At 22.5 ºC and 1.25 atm pressure, a sample of carbon dioxide gas occupies a volume of 2.65 L. How many moles of the gas are present?

Nov 13, 2017

$1.36 \times {10}^{- 1}$ ${\text{mol CO}}_{2}$

#### Explanation:

$P V = n R T$

We want to find the no. of moles, which is $n$, so

$n = \frac{P V}{R T}$

Here

• $\text{P = 1.25 atm}$
• $V = \text{2.65 L}$
• $R = \text{0.0821 atm(L)/mol(K)}$
• $T = {22.5}^{\circ} \text{C" +273.15 = "295.7 K}$

Now plug it into the formula

$n = \left(\left(\text{1.25 atm")("2.65 L"))/(("0.0821 atm(L)/mol(K)")("295.7 K}\right)\right)$

$n = \frac{3.3125}{24.273}$ $\text{mol}$

$n = 1.36 \times {10}^{- 1}$ ${\text{mol CO}}_{2}$