To solve this problem, we need to understand the significance of the equilibrium constant $K_c. \\$The equilibrium constant $K_c$ is a measure of the extent of a reaction at equilibrium.$\\$It is defined as the ratio of the concentration of products to the concentration of reactants,$\\$each raised to the power of their stoichiometric coefficients.$\\$Given:$\\ K_c = 1.6 \times 10^{12} \\$Interpretation:$\\$• A very large $K_c$ (much greater than 1) indicates that the equilibrium position is far to the right,$\\$meaning that the concentration of products is much greater than the concentration of reactants.$\\$• Conversely, a very small $K_c$ (much less than 1) would indicate that the equilibrium position is$\\$far to the left, meaning mostly reactants are present.$\\$Since $K_c = 1.6 \times 10^{12}$ is a very large number, it implies that at equilibrium,$\\$the system will contain mostly products.$\\$Therefore, the correct option is:$\\$Option 2: Mostly products.