Input interpretation
water + methane ⟶ hydrogen + carbon dioxide
Balanced equation
Balance the chemical equation algebraically: + ⟶ + Add stoichiometric coefficients, c_i, to the reactants and products: c_1 + c_2 ⟶ c_3 + c_4 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O and C: H: | 2 c_1 + 4 c_2 = 2 c_3 O: | c_1 = 2 c_4 C: | c_2 = c_4 Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set c_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 1 c_3 = 4 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 + ⟶ 4 +
Structures
+ ⟶ +
Names
water + methane ⟶ hydrogen + carbon dioxide
Reaction thermodynamics
Enthalpy
| water | methane | hydrogen | carbon dioxide molecular enthalpy | -285.8 kJ/mol | -74.6 kJ/mol | 0 kJ/mol | -393.5 kJ/mol total enthalpy | -571.7 kJ/mol | -74.6 kJ/mol | 0 kJ/mol | -393.5 kJ/mol | H_initial = -646.3 kJ/mol | | H_final = -393.5 kJ/mol | ΔH_rxn^0 | -393.5 kJ/mol - -646.3 kJ/mol = 252.8 kJ/mol (endothermic) | | |
Gibbs free energy
| water | methane | hydrogen | carbon dioxide molecular free energy | -237.1 kJ/mol | -51 kJ/mol | 0 kJ/mol | -394.4 kJ/mol total free energy | -474.2 kJ/mol | -51 kJ/mol | 0 kJ/mol | -394.4 kJ/mol | G_initial = -525.2 kJ/mol | | G_final = -394.4 kJ/mol | ΔG_rxn^0 | -394.4 kJ/mol - -525.2 kJ/mol = 130.8 kJ/mol (endergonic) | | |
Entropy
| water | methane | hydrogen | carbon dioxide molecular entropy | 69.91 J/(mol K) | 186 J/(mol K) | 115 J/(mol K) | 214 J/(mol K) total entropy | 139.8 J/(mol K) | 186 J/(mol K) | 460 J/(mol K) | 214 J/(mol K) | S_initial = 325.8 J/(mol K) | | S_final = 674 J/(mol K) | ΔS_rxn^0 | 674 J/(mol K) - 325.8 J/(mol K) = 348.2 J/(mol K) (endoentropic) | | |
Chemical names and formulas
| water | methane | hydrogen | carbon dioxide Hill formula | H_2O | CH_4 | H_2 | CO_2 name | water | methane | hydrogen | carbon dioxide IUPAC name | water | methane | molecular hydrogen | carbon dioxide