$2 KClO X_{3} \to 2 KCl + 3 O X_{2}$ . A sample of $49.0 g$ of $KClO X_{3}$ is heated and $80%$ of it decomposes (K = 39, Cl = 35.5, O = 16; $22.4 L mo l^{- 1}$ at STP). Find the volume of $O X_{2}$ evolved at STP in litres, to two decimal places.

Numerical answer type, answer in L, tolerance 0.005.

Answer: 10.75 L

n (KClO X_{3}) = 49.0/122.5 = 0.400

mol; decomposed

= 0.320

mol.

O X_{2}

= 0.320 \times 3/2 = 0.480

mol.

V = 0.480 \times 22.4 = 10.75 L