CuO + CuS = SO2 + Cu

CuO cupric oxide + CuS cupric sulfide ⟶ SO_2 sulfur dioxide + Cu copper

Balance the chemical equation algebraically: CuO + CuS ⟶ SO_2 + Cu Add stoichiometric coefficients, c_i, to the reactants and products: c_1 CuO + c_2 CuS ⟶ c_3 SO_2 + c_4 Cu Set the number of atoms in the reactants equal to the number of atoms in the products for Cu, O and S: Cu: | c_1 + c_2 = c_4 O: | c_1 = 2 c_3 S: | c_2 = c_3 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 = 1 c_4 = 3 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 CuO + CuS ⟶ SO_2 + 3 Cu

+ ⟶ +

cupric oxide + cupric sulfide ⟶ sulfur dioxide + copper

| cupric oxide | cupric sulfide | sulfur dioxide | copper molecular enthalpy | -157.3 kJ/mol | -53.1 kJ/mol | -296.8 kJ/mol | 0 kJ/mol total enthalpy | -314.6 kJ/mol | -53.1 kJ/mol | -296.8 kJ/mol | 0 kJ/mol | H_initial = -367.7 kJ/mol | | H_final = -296.8 kJ/mol | ΔH_rxn^0 | -296.8 kJ/mol - -367.7 kJ/mol = 70.9 kJ/mol (endothermic) | | |

| cupric oxide | cupric sulfide | sulfur dioxide | copper molecular entropy | 43 J/(mol K) | 67 J/(mol K) | 248 J/(mol K) | 33 J/(mol K) total entropy | 86 J/(mol K) | 67 J/(mol K) | 248 J/(mol K) | 99 J/(mol K) | S_initial = 153 J/(mol K) | | S_final = 347 J/(mol K) | ΔS_rxn^0 | 347 J/(mol K) - 153 J/(mol K) = 194 J/(mol K) (endoentropic) | | |

Construct the equilibrium constant, K, expression for: CuO + CuS ⟶ SO_2 + Cu 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: 2 CuO + CuS ⟶ SO_2 + 3 Cu 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 CuO | 2 | -2 CuS | 1 | -1 SO_2 | 1 | 1 Cu | 3 | 3 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression CuO | 2 | -2 | ([CuO])^(-2) CuS | 1 | -1 | ([CuS])^(-1) SO_2 | 1 | 1 | [SO2] Cu | 3 | 3 | ([Cu])^3 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 = ([CuO])^(-2) ([CuS])^(-1) [SO2] ([Cu])^3 = ([SO2] ([Cu])^3)/(([CuO])^2 [CuS])

Construct the rate of reaction expression for: CuO + CuS ⟶ SO_2 + Cu 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: 2 CuO + CuS ⟶ SO_2 + 3 Cu 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 CuO | 2 | -2 CuS | 1 | -1 SO_2 | 1 | 1 Cu | 3 | 3 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 CuO | 2 | -2 | -1/2 (Δ[CuO])/(Δt) CuS | 1 | -1 | -(Δ[CuS])/(Δt) SO_2 | 1 | 1 | (Δ[SO2])/(Δt) Cu | 3 | 3 | 1/3 (Δ[Cu])/(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 = -1/2 (Δ[CuO])/(Δt) = -(Δ[CuS])/(Δt) = (Δ[SO2])/(Δt) = 1/3 (Δ[Cu])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| cupric oxide | cupric sulfide | sulfur dioxide | copper formula | CuO | CuS | SO_2 | Cu Hill formula | CuO | CuS | O_2S | Cu name | cupric oxide | cupric sulfide | sulfur dioxide | copper

| cupric oxide | cupric sulfide | sulfur dioxide | copper molar mass | 79.545 g/mol | 95.61 g/mol | 64.06 g/mol | 63.546 g/mol phase | solid (at STP) | solid (at STP) | gas (at STP) | solid (at STP) melting point | 1326 °C | 220 °C | -73 °C | 1083 °C boiling point | 2000 °C | | -10 °C | 2567 °C density | 6.315 g/cm^3 | 4.6 g/cm^3 | 0.002619 g/cm^3 (at 25 °C) | 8.96 g/cm^3 solubility in water | insoluble | | | insoluble surface tension | | | 0.02859 N/m | dynamic viscosity | | 3.68×10^-5 Pa s (at 1250 °C) | 1.282×10^-5 Pa s (at 25 °C) | odor | | | | odorless