Answer is: volume of oxygen is 4.63 liters.
Balanced chemical reaction: 2C + O₂ → 2CO.
m(C) = 4.50 g.
n(C) = m(C) ÷ M(C).
n(C) = 4.50 g ÷ 12 g/mol.
n(C) = 0.375 mol.
From chemical reaction: n(C) : n(O₂) = 2 : 1.
n(O₂) = 0.1875 mol.
T = 48°C = 321.15 K.
p = 810 mmHg ÷ 760 mmHg/atm= 1.066 atm.
R = 0.08206
L·atm/mol·K.
Ideal gas law: p·V = n·R·T.
V(O₂) =
n·R·T / p.
V(O₂) =
0.1875 mol · 0.08206 L·atm/mol·K · 321.15 K / 1.066 atm.
V(O₂) =
4.63 L.