Question

How many litres of O₂ at STP are needed to complete the combustion of 39 g of liquid benzene as per equation given below?

\(2C_{6}H_{6}(l) + 15O_{2}(g) \longrightarrow 12CO_{2}(g) + 6H_{2}O (g) \)

(a) 84 l

(b) 74 l

(c) 11.2 l

(d) 22.4 l

Answer 1

Correct option is (a) 84 l

Moles of benzene undergoing combustion = \(\frac{39}{78} = 0.5\)

Volume of O₂ needed = \(\frac{15 \times 22.4 \times 0.5}2 = 84\ l\)