which reaction is exothermic?\no ch₄ + 2o₂ → co₂ + 2h₂o + 891 kj\no nh₄no₃ + h₂o + 25 kj → nh₄⁺(aq) +…
which reaction is exothermic?\no ch₄ + 2o₂ → co₂ + 2h₂o + 891 kj\no nh₄no₃ + h₂o + 25 kj → nh₄⁺(aq) + no₃⁻(aq)\no 2h₂o + 286 kj → 2h₂ + o₂\no n₂ + o₂ + 181 kj → 2no
Answer
Explanation:
Step1: Recall exothermic reaction concept
An exothermic reaction releases energy. In chemical - reaction equations, energy is shown on the product side for exothermic reactions.
Step2: Analyze each option
- For $\ce{CH4 + 2O2\rightarrow CO2 + 2H2O+891 kJ}$, energy is on the product side, so it is exothermic.
- For $\ce{NH4NO3 + H2O + 25 kJ\rightarrow NH4^{+}(aq)+NO3^{-}(aq)}$, energy is on the reactant side, so it is endothermic.
- For $\ce{2H2O + 286 kJ\rightarrow 2H2+O2}$, energy is on the reactant side, so it is endothermic.
- For $\ce{N2 + O2+181 kJ\rightarrow 2NO}$, energy is on the reactant side, so it is endothermic.
Answer:
$\ce{CH4 + 2O2\rightarrow CO2 + 2H2O + 891 kJ}$