Input interpretation
water + iron ⟶ hydrogen + iron(III) oxide
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 Fe: H: | 2 c_1 = 2 c_3 O: | c_1 = 3 c_4 Fe: | c_2 = 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_4 = 1 and solve the system of equations for the remaining coefficients: c_1 = 3 c_2 = 2 c_3 = 3 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 + 2 ⟶ 3 +
Structures
+ ⟶ +
Names
water + iron ⟶ hydrogen + iron(III) oxide
Reaction thermodynamics
Enthalpy
| water | iron | hydrogen | iron(III) oxide molecular enthalpy | -285.8 kJ/mol | 0 kJ/mol | 0 kJ/mol | -826 kJ/mol total enthalpy | -857.5 kJ/mol | 0 kJ/mol | 0 kJ/mol | -826 kJ/mol | H_initial = -857.5 kJ/mol | | H_final = -826 kJ/mol | ΔH_rxn^0 | -826 kJ/mol - -857.5 kJ/mol = 31.49 kJ/mol (endothermic) | | |
Entropy
| water | iron | hydrogen | iron(III) oxide molecular entropy | 69.91 J/(mol K) | 27 J/(mol K) | 115 J/(mol K) | 90 J/(mol K) total entropy | 209.7 J/(mol K) | 54 J/(mol K) | 345 J/(mol K) | 90 J/(mol K) | S_initial = 263.7 J/(mol K) | | S_final = 435 J/(mol K) | ΔS_rxn^0 | 435 J/(mol K) - 263.7 J/(mol K) = 171.3 J/(mol K) (endoentropic) | | |
Chemical names and formulas
| water | iron | hydrogen | iron(III) oxide Hill formula | H_2O | Fe | H_2 | Fe_2O_3 name | water | iron | hydrogen | iron(III) oxide IUPAC name | water | iron | molecular hydrogen |
Substance properties
| water | iron | hydrogen | iron(III) oxide molar mass | 18.015 g/mol | 55.845 g/mol | 2.016 g/mol | 159.69 g/mol phase | liquid (at STP) | solid (at STP) | gas (at STP) | solid (at STP) melting point | 0 °C | 1535 °C | -259.2 °C | 1565 °C boiling point | 99.9839 °C | 2750 °C | -252.8 °C | density | 1 g/cm^3 | 7.874 g/cm^3 | 8.99×10^-5 g/cm^3 (at 0 °C) | 5.26 g/cm^3 solubility in water | | insoluble | | insoluble surface tension | 0.0728 N/m | | | dynamic viscosity | 8.9×10^-4 Pa s (at 25 °C) | | 8.9×10^-6 Pa s (at 25 °C) | odor | odorless | | odorless | odorless
Units
