Question

what is the volume in liters of 4.2 moles methane gas, at 26degree C and 1.40 atm?

Answer 1

assuming that the gas is ideal, we use the formula for ideal gases:
PV = nRT
where
P = pressure (in atm)
V = volume (in L)
n = number of moles
R = gas constant (0.0821 L*atm/mol-K)
T = temperature (in Kelvin)
we first convert the 26 degrees Celsius to Kelvin:
26 + 273.15 = 299.15 K
substituting,
(1.40)(V) = (4.2)(0.0821)(299.15)
V = (4.2)(0.0821)(299.15)/(1.40)
V = 73.68 L

hope this helps~ :)

Answer 2

An ideal Gas is allowed to expand from 7.40 L to 62.9 L at a constant temperature.
by what factor does the volume increase?

The pressure will (increase/decrease) by that same factor?

If the initial pressure was 137 atm, what is the final pressure?