=3‌ moles ‌ Step 2: Add up all the moles for the total initial amount ni‌=nO2+nN2+nCO2 ‌=2+1+3=6‌ moles ‌ Step 3: Find out how many moles are left after removing all the oxygen gas Only nitrogen ( N2 ) and carbon dioxide ( CO2 ) are left. nf=nN2+nCO2=1+3=4‌ moles ‌ Step 4: Relate pressure and moles using the formula pV=nRT Since temperature and volume stay the same, the pressure is directly proportional to the number of moles. So, ‌
