Question

How many moles of gas are there in a 45.0 L container at 25.0 °C and 500.0 mm Hg?

Answer 1

You can solve this by utilizing the ideal gas law, PV=nRT. P is pressure, V is volume, n is the number of moles, R is a constant (depends on the unit of pressure), and T is the temperature (in Kelvins).

500.0mmHg- convert to atm

=0.65789atm (do sig figs last)

25.0 C- convert to K

25.0 +273= 298K

PV=nRT

0.65789atm times 45.0L equals n (the variable) times R (0.08206L atm mol^-1 K^-1) times 298K

Isolate the variable, n and plug into a calculator.

I hope this helped!

Answer 2

Answer: The moles of gas is 1.21 moles.

Step-by-step explanation:

To calculate the moles of gas, we use the equation given by ideal gas which follows:

`PV=nRT`

where,

P = pressure of the gas = 500.0 mmHg

V = Volume of the gas = 45.0 L

T = Temperature of the gas =
`25^oC=[25+273]K=298K`

R = Gas constant =
`62.364\text{ L.mmHg }mol^(-1)K^(-1)`

n = number of moles of gas = ?

Putting values in above equation, we get:

`500.0mmHg* 45.0L=n* 62.3637\text{ L.mmHg }mol^(-1)K^(-1)* 298K\\\\n=(500.0* 45.0)/(62.364* 298)=1.21mol`

Hence, the moles of gas is 1.21 moles.