Na2SO3 + CuCl2 = NaCl + CuSO3

Na_2SO_3 sodium sulfite + CuCl_2 copper(II) chloride ⟶ NaCl sodium chloride + CuSO3

Balance the chemical equation algebraically: Na_2SO_3 + CuCl_2 ⟶ NaCl + CuSO3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Na_2SO_3 + c_2 CuCl_2 ⟶ c_3 NaCl + c_4 CuSO3 Set the number of atoms in the reactants equal to the number of atoms in the products for Na, O, S, Cl and Cu: Na: | 2 c_1 = c_3 O: | 3 c_1 = 3 c_4 S: | c_1 = c_4 Cl: | 2 c_2 = c_3 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 = 2 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Na_2SO_3 + CuCl_2 ⟶ 2 NaCl + CuSO3

+ ⟶ + CuSO3

sodium sulfite + copper(II) chloride ⟶ sodium chloride + CuSO3

Construct the equilibrium constant, K, expression for: Na_2SO_3 + CuCl_2 ⟶ NaCl + CuSO3 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: Na_2SO_3 + CuCl_2 ⟶ 2 NaCl + CuSO3 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 Na_2SO_3 | 1 | -1 CuCl_2 | 1 | -1 NaCl | 2 | 2 CuSO3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Na_2SO_3 | 1 | -1 | ([Na2SO3])^(-1) CuCl_2 | 1 | -1 | ([CuCl2])^(-1) NaCl | 2 | 2 | ([NaCl])^2 CuSO3 | 1 | 1 | [CuSO3] 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 = ([Na2SO3])^(-1) ([CuCl2])^(-1) ([NaCl])^2 [CuSO3] = (([NaCl])^2 [CuSO3])/([Na2SO3] [CuCl2])

Construct the rate of reaction expression for: Na_2SO_3 + CuCl_2 ⟶ NaCl + CuSO3 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: Na_2SO_3 + CuCl_2 ⟶ 2 NaCl + CuSO3 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 Na_2SO_3 | 1 | -1 CuCl_2 | 1 | -1 NaCl | 2 | 2 CuSO3 | 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 Na_2SO_3 | 1 | -1 | -(Δ[Na2SO3])/(Δt) CuCl_2 | 1 | -1 | -(Δ[CuCl2])/(Δt) NaCl | 2 | 2 | 1/2 (Δ[NaCl])/(Δt) CuSO3 | 1 | 1 | (Δ[CuSO3])/(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[Na2SO3])/(Δt) = -(Δ[CuCl2])/(Δt) = 1/2 (Δ[NaCl])/(Δt) = (Δ[CuSO3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium sulfite | copper(II) chloride | sodium chloride | CuSO3 formula | Na_2SO_3 | CuCl_2 | NaCl | CuSO3 Hill formula | Na_2O_3S | Cl_2Cu | ClNa | CuO3S name | sodium sulfite | copper(II) chloride | sodium chloride | IUPAC name | disodium sulfite | dichlorocopper | sodium chloride |

| sodium sulfite | copper(II) chloride | sodium chloride | CuSO3 molar mass | 126.04 g/mol | 134.4 g/mol | 58.44 g/mol | 143.6 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | melting point | 500 °C | 620 °C | 801 °C | boiling point | | | 1413 °C | density | 2.63 g/cm^3 | 3.386 g/cm^3 | 2.16 g/cm^3 | solubility in water | | | soluble | odor | | | odorless |