Ideal Gas Law states that Volume,pressure, temperatures and numbers of moles are interrelates.
P = nRT/ V
n = 0.25 mole
R = 0.0821 L.atm/ mole
T = 70.0 ° C
V = 1.25 L
- remember that the volume must be converted first to liter.
- and always that temperature would be in Kelvin.
*70.0°C will be 343 K because ( 70.0 + 273.15 K )(constant given)
* 1250 ml will be 1.25 L because every 1000 ml is equal to 1 liter ) (cancel)
P = n RT/ V
= (0.25 mole ) (0.0821 L atm / mole K )( 343 K) / 1.25 L
= 0.56 atm
therefore, the combine ideal gas is 0.56 atm