A combustible mixture of \(\mathrm{CO}\) and air containing \(15 \% \mathrm{CO}\) by volume enters a combustion chamber at \(0.5 \mathrm{~kg} / \mathrm{s}\). The pressure, temperature and the mean velocity of the stream are \(2.1 \mathrm{bar}, 125^{\circ} \mathrm{C}\) and \(120 \mathrm{~m} / \mathrm{s}\), while the environmental pressure and temperature are \(1 \mathrm{bar}\) and \(25^{\circ} \mathrm{C}\), respectively. Calculate the exergy rate of the stream.