H2O + Cu = H2 + CuO

H_2O water + Cu copper ⟶ H_2 hydrogen + CuO cupric oxide

Balance the chemical equation algebraically: H_2O + Cu ⟶ H_2 + CuO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O + c_2 Cu ⟶ c_3 H_2 + c_4 CuO Set the number of atoms in the reactants equal to the number of atoms in the products for H, O and Cu: H: | 2 c_1 = 2 c_3 O: | c_1 = c_4 Cu: | 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 1 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | H_2O + Cu ⟶ H_2 + CuO

+ ⟶ +

water + copper ⟶ hydrogen + cupric oxide

| water | copper | hydrogen | cupric oxide molecular enthalpy | -285.8 kJ/mol | 0 kJ/mol | 0 kJ/mol | -157.3 kJ/mol total enthalpy | -285.8 kJ/mol | 0 kJ/mol | 0 kJ/mol | -157.3 kJ/mol | H_initial = -285.8 kJ/mol | | H_final = -157.3 kJ/mol | ΔH_rxn^0 | -157.3 kJ/mol - -285.8 kJ/mol = 128.5 kJ/mol (endothermic) | | |

| water | copper | hydrogen | cupric oxide molecular entropy | 69.91 J/(mol K) | 33 J/(mol K) | 115 J/(mol K) | 43 J/(mol K) total entropy | 69.91 J/(mol K) | 33 J/(mol K) | 115 J/(mol K) | 43 J/(mol K) | S_initial = 102.9 J/(mol K) | | S_final = 158 J/(mol K) | ΔS_rxn^0 | 158 J/(mol K) - 102.9 J/(mol K) = 55.09 J/(mol K) (endoentropic) | | |

Construct the equilibrium constant, K, expression for: H_2O + Cu ⟶ H_2 + CuO Plan: • Balance the chemical equation. • Determine the stoichiometric numbers. • Assemble the activity expression for each chemical species. • Use the activity expressions to build the equilibrium constant expression. Write the balanced chemical equation: H_2O + Cu ⟶ H_2 + CuO Assign stoichiometric numbers, ν_i, using the stoichiometric coefficients, c_i, from the balanced chemical equation in the following manner: ν_i = -c_i for reactants and ν_i = c_i for products: chemical species | c_i | ν_i H_2O | 1 | -1 Cu | 1 | -1 H_2 | 1 | 1 CuO | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2O | 1 | -1 | ([H2O])^(-1) Cu | 1 | -1 | ([Cu])^(-1) H_2 | 1 | 1 | [H2] CuO | 1 | 1 | [CuO] The equilibrium constant symbol in the concentration basis is: K_c Mulitply the activity expressions to arrive at the K_c expression: Answer: | | K_c = ([H2O])^(-1) ([Cu])^(-1) [H2] [CuO] = ([H2] [CuO])/([H2O] [Cu])

Construct the rate of reaction expression for: H_2O + Cu ⟶ H_2 + CuO Plan: • Balance the chemical equation. • Determine the stoichiometric numbers. • Assemble the rate term for each chemical species. • Write the rate of reaction expression. Write the balanced chemical equation: H_2O + Cu ⟶ H_2 + CuO Assign stoichiometric numbers, ν_i, using the stoichiometric coefficients, c_i, from the balanced chemical equation in the following manner: ν_i = -c_i for reactants and ν_i = c_i for products: chemical species | c_i | ν_i H_2O | 1 | -1 Cu | 1 | -1 H_2 | 1 | 1 CuO | 1 | 1 The rate term for each chemical species, B_i, is 1/ν_i(Δ[B_i])/(Δt) where [B_i] is the amount concentration and t is time: chemical species | c_i | ν_i | rate term H_2O | 1 | -1 | -(Δ[H2O])/(Δt) Cu | 1 | -1 | -(Δ[Cu])/(Δt) H_2 | 1 | 1 | (Δ[H2])/(Δt) CuO | 1 | 1 | (Δ[CuO])/(Δt) (for infinitesimal rate of change, replace Δ with d) Set the rate terms equal to each other to arrive at the rate expression: Answer: | | rate = -(Δ[H2O])/(Δt) = -(Δ[Cu])/(Δt) = (Δ[H2])/(Δt) = (Δ[CuO])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| water | copper | hydrogen | cupric oxide formula | H_2O | Cu | H_2 | CuO name | water | copper | hydrogen | cupric oxide IUPAC name | water | copper | molecular hydrogen |

| water | copper | hydrogen | cupric oxide molar mass | 18.015 g/mol | 63.546 g/mol | 2.016 g/mol | 79.545 g/mol phase | liquid (at STP) | solid (at STP) | gas (at STP) | solid (at STP) melting point | 0 °C | 1083 °C | -259.2 °C | 1326 °C boiling point | 99.9839 °C | 2567 °C | -252.8 °C | 2000 °C density | 1 g/cm^3 | 8.96 g/cm^3 | 8.99×10^-5 g/cm^3 (at 0 °C) | 6.315 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 |