Final answer:
Without the specific binding energies, we cannot calculate the q value for the neutron and oxygen reaction to determine if it's exothermic or endothermic. Other reactions are classified as exothermic if they release energy or endothermic if they absorb energy.
Step-by-step explanation:
To calculate the q value of the reaction ¹₀n + ¹⁷₈O → ⁴₂He + ¹⁴₆C, we compare the mass of the reactants to the mass of the products. When more energy is released than absorbed, the reaction is exothermic. If more energy is absorbed than released, the reaction is endothermic. Unfortunately, without the specific binding energies or mass defect information, we cannot calculate the q value for this nuclear reaction nor definitively state whether it is endothermic or exothermic. To determine the nature of chemical reactions provided in the examples: For the reaction CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) + 213 kcal, it is exothermic because energy is released. The reaction N2(g) + O2(g) + 45 kcal → 2NO(g) is endothermic since energy must be supplied.
Similarly, other reactions provided in the exercise are classified based on whether they absorb or release energy. Increasing temperature in an endothermic reaction, such as the decomposition of N2O4 (g) → 2NO2(g), will shift equilibrium to favor the formation of the products.