The decomposition $2 H X_{2} O X_{2} 2 H X_{2} O + O X_{2}$ of $50.0 mL$ of solution gives $33.6 mL$ of $O X_{2}$ (at STP, molar volume $22.4 L mo l^{- 1}$ ) in the first $10.0 min$ . Taking the volume as constant, find the average rate of disappearance of $H X_{2} O X_{2}$ in units of $1 0^{- 3} M mi n^{- 1}$ (two decimal places).

Numerical answer type, answer in 1e-3 M/min, tolerance 0.01.

Answer: 6 1e-3 M/min

Moles of

O X_{2}

33.6 \times 1 0^{- 3} /22.4 = 0.0015

mol;

H X_{2} O X_{2}

consumed is twice this,

0.0030

mol, i.e.

0.0600 M

0.0500

L. Average rate

= 0.0600/10.0 = 6.00 \times 1 0^{- 3} M mi n^{- 1}