Answer : The mass of oxygen gas is, 24.94 grams
Explanation :
Using ideal gas equation :

or,

where,
P = pressure of gas = 1.83 atm
V = volume of gas = 10.5 L
T = temperature of gas =

R = gas constant = 0.0821 L.atm/mole.K
n = number of moles of oxygen gas
w = mass of oxygen gas = ?
M = molar mass of oxygen gas = 32 g/mole
Now put all the given values in the above law, we get


Therefore, the mass of oxygen gas is, 24.94 grams