Input interpretation
KBr potassium bromide + H_2SeO_4 selenic acid ⟶ H_2O water + Br_2 bromine + SeBr_4 selenium tetrabromide + KHSeO4
Balanced equation
Balance the chemical equation algebraically: KBr + H_2SeO_4 ⟶ H_2O + Br_2 + SeBr_4 + KHSeO4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 KBr + c_2 H_2SeO_4 ⟶ c_3 H_2O + c_4 Br_2 + c_5 SeBr_4 + c_6 KHSeO4 Set the number of atoms in the reactants equal to the number of atoms in the products for Br, K, H, O and Se: Br: | c_1 = 2 c_4 + 4 c_5 K: | c_1 = c_6 H: | 2 c_2 = 2 c_3 + c_6 O: | 4 c_2 = c_3 + 4 c_6 Se: | c_2 = c_5 + c_6 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 = 6 c_2 = 7 c_3 = 4 c_4 = 1 c_5 = 1 c_6 = 6 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 6 KBr + 7 H_2SeO_4 ⟶ 4 H_2O + Br_2 + SeBr_4 + 6 KHSeO4
Structures
+ ⟶ + + + KHSeO4
Names
potassium bromide + selenic acid ⟶ water + bromine + selenium tetrabromide + KHSeO4
Equilibrium constant
![Construct the equilibrium constant, K, expression for: KBr + H_2SeO_4 ⟶ H_2O + Br_2 + SeBr_4 + KHSeO4 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: 6 KBr + 7 H_2SeO_4 ⟶ 4 H_2O + Br_2 + SeBr_4 + 6 KHSeO4 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 KBr | 6 | -6 H_2SeO_4 | 7 | -7 H_2O | 4 | 4 Br_2 | 1 | 1 SeBr_4 | 1 | 1 KHSeO4 | 6 | 6 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression KBr | 6 | -6 | ([KBr])^(-6) H_2SeO_4 | 7 | -7 | ([H2SeO4])^(-7) H_2O | 4 | 4 | ([H2O])^4 Br_2 | 1 | 1 | [Br2] SeBr_4 | 1 | 1 | [SeBr4] KHSeO4 | 6 | 6 | ([KHSeO4])^6 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 = ([KBr])^(-6) ([H2SeO4])^(-7) ([H2O])^4 [Br2] [SeBr4] ([KHSeO4])^6 = (([H2O])^4 [Br2] [SeBr4] ([KHSeO4])^6)/(([KBr])^6 ([H2SeO4])^7)](../image_source/e590647f5faff4805078451cef388592.png)
Construct the equilibrium constant, K, expression for: KBr + H_2SeO_4 ⟶ H_2O + Br_2 + SeBr_4 + KHSeO4 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: 6 KBr + 7 H_2SeO_4 ⟶ 4 H_2O + Br_2 + SeBr_4 + 6 KHSeO4 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 KBr | 6 | -6 H_2SeO_4 | 7 | -7 H_2O | 4 | 4 Br_2 | 1 | 1 SeBr_4 | 1 | 1 KHSeO4 | 6 | 6 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression KBr | 6 | -6 | ([KBr])^(-6) H_2SeO_4 | 7 | -7 | ([H2SeO4])^(-7) H_2O | 4 | 4 | ([H2O])^4 Br_2 | 1 | 1 | [Br2] SeBr_4 | 1 | 1 | [SeBr4] KHSeO4 | 6 | 6 | ([KHSeO4])^6 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 = ([KBr])^(-6) ([H2SeO4])^(-7) ([H2O])^4 [Br2] [SeBr4] ([KHSeO4])^6 = (([H2O])^4 [Br2] [SeBr4] ([KHSeO4])^6)/(([KBr])^6 ([H2SeO4])^7)
Rate of reaction
![Construct the rate of reaction expression for: KBr + H_2SeO_4 ⟶ H_2O + Br_2 + SeBr_4 + KHSeO4 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: 6 KBr + 7 H_2SeO_4 ⟶ 4 H_2O + Br_2 + SeBr_4 + 6 KHSeO4 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 KBr | 6 | -6 H_2SeO_4 | 7 | -7 H_2O | 4 | 4 Br_2 | 1 | 1 SeBr_4 | 1 | 1 KHSeO4 | 6 | 6 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 KBr | 6 | -6 | -1/6 (Δ[KBr])/(Δt) H_2SeO_4 | 7 | -7 | -1/7 (Δ[H2SeO4])/(Δt) H_2O | 4 | 4 | 1/4 (Δ[H2O])/(Δt) Br_2 | 1 | 1 | (Δ[Br2])/(Δt) SeBr_4 | 1 | 1 | (Δ[SeBr4])/(Δt) KHSeO4 | 6 | 6 | 1/6 (Δ[KHSeO4])/(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 = -1/6 (Δ[KBr])/(Δt) = -1/7 (Δ[H2SeO4])/(Δt) = 1/4 (Δ[H2O])/(Δt) = (Δ[Br2])/(Δt) = (Δ[SeBr4])/(Δt) = 1/6 (Δ[KHSeO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)](../image_source/37bbd0301ffeeeaf1896042066326a98.png)
Construct the rate of reaction expression for: KBr + H_2SeO_4 ⟶ H_2O + Br_2 + SeBr_4 + KHSeO4 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: 6 KBr + 7 H_2SeO_4 ⟶ 4 H_2O + Br_2 + SeBr_4 + 6 KHSeO4 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 KBr | 6 | -6 H_2SeO_4 | 7 | -7 H_2O | 4 | 4 Br_2 | 1 | 1 SeBr_4 | 1 | 1 KHSeO4 | 6 | 6 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 KBr | 6 | -6 | -1/6 (Δ[KBr])/(Δt) H_2SeO_4 | 7 | -7 | -1/7 (Δ[H2SeO4])/(Δt) H_2O | 4 | 4 | 1/4 (Δ[H2O])/(Δt) Br_2 | 1 | 1 | (Δ[Br2])/(Δt) SeBr_4 | 1 | 1 | (Δ[SeBr4])/(Δt) KHSeO4 | 6 | 6 | 1/6 (Δ[KHSeO4])/(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 = -1/6 (Δ[KBr])/(Δt) = -1/7 (Δ[H2SeO4])/(Δt) = 1/4 (Δ[H2O])/(Δt) = (Δ[Br2])/(Δt) = (Δ[SeBr4])/(Δt) = 1/6 (Δ[KHSeO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| potassium bromide | selenic acid | water | bromine | selenium tetrabromide | KHSeO4 formula | KBr | H_2SeO_4 | H_2O | Br_2 | SeBr_4 | KHSeO4 Hill formula | BrK | H_2O_4Se | H_2O | Br_2 | Br_4Se | HKO4Se name | potassium bromide | selenic acid | water | bromine | selenium tetrabromide | IUPAC name | potassium bromide | selenic acid | water | molecular bromine | |