Input interpretation
CuSO_4 copper(II) sulfate + Na_2S_2O_3 sodium hyposulfite ⟶ Na_2SO_4 sodium sulfate + Na2S4O6 + Cu2S2O3
Balanced equation
Balance the chemical equation algebraically: CuSO_4 + Na_2S_2O_3 ⟶ Na_2SO_4 + Na2S4O6 + Cu2S2O3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 CuSO_4 + c_2 Na_2S_2O_3 ⟶ c_3 Na_2SO_4 + c_4 Na2S4O6 + c_5 Cu2S2O3 Set the number of atoms in the reactants equal to the number of atoms in the products for Cu, O, S and Na: Cu: | c_1 = 2 c_5 O: | 4 c_1 + 3 c_2 = 4 c_3 + 6 c_4 + 3 c_5 S: | c_1 + 2 c_2 = c_3 + 4 c_4 + 2 c_5 Na: | 2 c_2 = 2 c_3 + 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 = 2 c_2 = 3 c_3 = 2 c_4 = 1 c_5 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 CuSO_4 + 3 Na_2S_2O_3 ⟶ 2 Na_2SO_4 + Na2S4O6 + Cu2S2O3
Structures
+ ⟶ + Na2S4O6 + Cu2S2O3
Names
copper(II) sulfate + sodium hyposulfite ⟶ sodium sulfate + Na2S4O6 + Cu2S2O3
Equilibrium constant
Construct the equilibrium constant, K, expression for: CuSO_4 + Na_2S_2O_3 ⟶ Na_2SO_4 + Na2S4O6 + Cu2S2O3 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 CuSO_4 + 3 Na_2S_2O_3 ⟶ 2 Na_2SO_4 + Na2S4O6 + Cu2S2O3 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 CuSO_4 | 2 | -2 Na_2S_2O_3 | 3 | -3 Na_2SO_4 | 2 | 2 Na2S4O6 | 1 | 1 Cu2S2O3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression CuSO_4 | 2 | -2 | ([CuSO4])^(-2) Na_2S_2O_3 | 3 | -3 | ([Na2S2O3])^(-3) Na_2SO_4 | 2 | 2 | ([Na2SO4])^2 Na2S4O6 | 1 | 1 | [Na2S4O6] Cu2S2O3 | 1 | 1 | [Cu2S2O3] 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 = ([CuSO4])^(-2) ([Na2S2O3])^(-3) ([Na2SO4])^2 [Na2S4O6] [Cu2S2O3] = (([Na2SO4])^2 [Na2S4O6] [Cu2S2O3])/(([CuSO4])^2 ([Na2S2O3])^3)
Rate of reaction
Construct the rate of reaction expression for: CuSO_4 + Na_2S_2O_3 ⟶ Na_2SO_4 + Na2S4O6 + Cu2S2O3 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 CuSO_4 + 3 Na_2S_2O_3 ⟶ 2 Na_2SO_4 + Na2S4O6 + Cu2S2O3 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 CuSO_4 | 2 | -2 Na_2S_2O_3 | 3 | -3 Na_2SO_4 | 2 | 2 Na2S4O6 | 1 | 1 Cu2S2O3 | 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 CuSO_4 | 2 | -2 | -1/2 (Δ[CuSO4])/(Δt) Na_2S_2O_3 | 3 | -3 | -1/3 (Δ[Na2S2O3])/(Δt) Na_2SO_4 | 2 | 2 | 1/2 (Δ[Na2SO4])/(Δt) Na2S4O6 | 1 | 1 | (Δ[Na2S4O6])/(Δt) Cu2S2O3 | 1 | 1 | (Δ[Cu2S2O3])/(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[CuSO4])/(Δt) = -1/3 (Δ[Na2S2O3])/(Δt) = 1/2 (Δ[Na2SO4])/(Δt) = (Δ[Na2S4O6])/(Δt) = (Δ[Cu2S2O3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| copper(II) sulfate | sodium hyposulfite | sodium sulfate | Na2S4O6 | Cu2S2O3 formula | CuSO_4 | Na_2S_2O_3 | Na_2SO_4 | Na2S4O6 | Cu2S2O3 Hill formula | CuO_4S | Na_2O_3S_2 | Na_2O_4S | Na2O6S4 | Cu2O3S2 name | copper(II) sulfate | sodium hyposulfite | sodium sulfate | | IUPAC name | copper sulfate | | disodium sulfate | |
Substance properties
| copper(II) sulfate | sodium hyposulfite | sodium sulfate | Na2S4O6 | Cu2S2O3 molar mass | 159.6 g/mol | 158.1 g/mol | 142.04 g/mol | 270.2 g/mol | 239.2 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | | melting point | 200 °C | 48 °C | 884 °C | | boiling point | | 100 °C | 1429 °C | | density | 3.603 g/cm^3 | 1.67 g/cm^3 | 2.68 g/cm^3 | | solubility in water | | | soluble | | odor | | odorless | | |
Units