Question

A 10.2−g sample of dinitrogen monoxide is confined in a 5.74−L vessel. What is the pressure (in atm) at 125°C?

Answer 1

The pressure of `"N"_2"O"` will be `"1.32 atm"` under the conditions given.

Explanation:

Use the ideal gas law equation:

`PV=nRT`,

where:

`P` is pressure, `V` is volume, `n` is moles, `R` is the gas constant, and `T` is the temperature in Kelvins.

Organize the data:

Known/Given

`V="5.74 L"`

`n= ("mass in g")/("molar mass")=(10.2color(red)cancel(color(black)("g N"_2"O")))/(44.013color(red)cancel(color(black)("g N"_2"O"))/("mol N"_2"O"))="0.2317 mol N"_2"O"`

`R=0.0820575" L atm K"^(-1) "mol"^(-1)"`
https://katmarsoftware.com/gconvals.htm

`T=125^@"C+273.15 = 398 K"`

Unknown

`P`

Solution

Rearrange the equation to isolate `P`. Plug in the known/given values and solve.

`P=(nRT)/V`

`P=((0.2317color(red)cancel(color(black)("mol"))xx0.0820575color(red)cancel(color(black)("L")) "atm" color(red)cancel(color(black)("K"))^(-1) color(red)cancel(color(black)("mol"))^(-1)xx398color(red)cancel(color(black)("K"))))/(5.74color(red)cancel(color(black)("K")))="1.32 atm"`