Question

$N_2$ is found in a litre flask under 100kPa pressure and $O_2$ is found in another 3 litre flask under 320 kPa pressure. If the two flasks are connected, the resultant pressures is

• A. 310 kPa
• B. 210 kPa
• C. 420 kPa
• D. 365 kPa
• E. 265 kPa

Answer 1

The correct option is E

265 kPa

The key idea is that total number of moles are the same initially and finally. Also, the temperature remains constant.
Hence, PV = constant.
Total volume = 4 litres.
Total pressure = $\frac{RT}{V}=\frac{(100+960)}{4}=265kPa$