Question

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?

Answer 1

`1.36 xx 10^(-1)` `"mol CO"_2`

Explanation:

`PV=nRT`

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

`n= (PV)/(RT)`

Here

• `"P = 1.25 atm"`
• `V = "2.65 L"`
• `R= "0.0821 atm(L)/mol(K)"`
• `T = 22.5^@"C" +273.15 = "295.7 K"`

Now plug it into the formula

`n = (("1.25 atm")("2.65 L"))/(("0.0821 atm(L)/mol(K)")("295.7 K"))`

`n = 3.3125/24.273` `"mol"`

`n = 1.36 xx 10^(-1)` `"mol CO"_2`