Question

What is the temperature of a 25.0 g sample of neon gas that exerts a pressure of .922 atm and has a volume of 3.25 L?

Answer 1

The temperature of the neon sample will be 29.5 K.

Explanation:

First convert mass to moles by dividing the given mass of the substance by its molar mass. Then use the ideal gas law to determine its temperature in Kelvins.

Moles of Neon

The molar mass of neon is `"20.180 g/mol"`.

`25.0cancel"g Ne"xx(1"mol Ne")/(20.180cancel"g Ne")="1.23885 mol Ne"`

Ideal Gas Law

The equation for the ideal gas law is `PV=nRT`, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvins.

Given/Known
`P="0.922 atm"`
`V="3.25 L"`
`n="1.23885 mol"`
`R="0.08206 L atm K"^(-1) "mol"^(-1)"`
https://en.m.wikipedia.org/wiki/Gas_constant

Unknown
`T=???`

Solution
Rearrange the ideal gas law equation to isolate temperature and substitute the known values into the equation, then solve.

`PV=nRT`

`T=(PV)/(nR)`

`T=((0.922cancel"atm"xx3.25cancel"L"))/((1.23885cancel"mol"xx0.08206cancel"L"·cancel"atm"·"K"^(-1)· cancel"mol"^(-1)))="29.5 K"` rounded to three significant figures