0.5 g of an organic compound (X) with 60% carbon will produce ______ $$\times 10^{-1}$$ g of CO$$_2$$ on complete combustion.

When 0.5 g of the organic compound X containing 60% carbon undergoes complete combustion, the mass of carbon in the compound can be determined.

The mass of carbon in the compound is calculated as $$\text{Mass of C} = 0.5 \times \frac{60}{100} = 0.3$$ g.

From this mass, the number of moles of carbon is found by dividing by the molar mass of carbon:

$$n_C = \frac{0.3}{12} = 0.025$$ mol.

Under complete combustion, each mole of carbon produces one mole of carbon dioxide according to the reaction:

$$C + O_2 \rightarrow CO_2$$

Thus, the number of moles of CO₂ formed is $$n_{CO_2} = 0.025$$ mol.

The mass of CO₂ produced is then calculated by multiplying by its molar mass:

$$m_{CO_2} = 0.025 \times 44 = 1.1$$ g $$= 11 \times 10^{-1}$$ g.

The correct answer is 11.