Input interpretation
KOH potassium hydroxide + SeCl_4 selenium tetrachloride ⟶ H_2O water + KCl potassium chloride + H_2SeO_3 selenious acid
Balanced equation
Balance the chemical equation algebraically: KOH + SeCl_4 ⟶ H_2O + KCl + H_2SeO_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 KOH + c_2 SeCl_4 ⟶ c_3 H_2O + c_4 KCl + c_5 H_2SeO_3 Set the number of atoms in the reactants equal to the number of atoms in the products for H, K, O, Cl and Se: H: | c_1 = 2 c_3 + 2 c_5 K: | c_1 = c_4 O: | c_1 = c_3 + 3 c_5 Cl: | 4 c_2 = c_4 Se: | c_2 = c_5 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 = 4 c_2 = 1 c_3 = 1 c_4 = 4 c_5 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 4 KOH + SeCl_4 ⟶ H_2O + 4 KCl + H_2SeO_3
Structures
+ ⟶ + +
Names
potassium hydroxide + selenium tetrachloride ⟶ water + potassium chloride + selenious acid
Equilibrium constant
Construct the equilibrium constant, K, expression for: KOH + SeCl_4 ⟶ H_2O + KCl + H_2SeO_3 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: 4 KOH + SeCl_4 ⟶ H_2O + 4 KCl + H_2SeO_3 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 KOH | 4 | -4 SeCl_4 | 1 | -1 H_2O | 1 | 1 KCl | 4 | 4 H_2SeO_3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression KOH | 4 | -4 | ([KOH])^(-4) SeCl_4 | 1 | -1 | ([SeCl4])^(-1) H_2O | 1 | 1 | [H2O] KCl | 4 | 4 | ([KCl])^4 H_2SeO_3 | 1 | 1 | [H2SeO3] 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 = ([KOH])^(-4) ([SeCl4])^(-1) [H2O] ([KCl])^4 [H2SeO3] = ([H2O] ([KCl])^4 [H2SeO3])/(([KOH])^4 [SeCl4])
Rate of reaction
Construct the rate of reaction expression for: KOH + SeCl_4 ⟶ H_2O + KCl + H_2SeO_3 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: 4 KOH + SeCl_4 ⟶ H_2O + 4 KCl + H_2SeO_3 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 KOH | 4 | -4 SeCl_4 | 1 | -1 H_2O | 1 | 1 KCl | 4 | 4 H_2SeO_3 | 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 KOH | 4 | -4 | -1/4 (Δ[KOH])/(Δt) SeCl_4 | 1 | -1 | -(Δ[SeCl4])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) KCl | 4 | 4 | 1/4 (Δ[KCl])/(Δt) H_2SeO_3 | 1 | 1 | (Δ[H2SeO3])/(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 = -1/4 (Δ[KOH])/(Δt) = -(Δ[SeCl4])/(Δt) = (Δ[H2O])/(Δt) = 1/4 (Δ[KCl])/(Δt) = (Δ[H2SeO3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| potassium hydroxide | selenium tetrachloride | water | potassium chloride | selenious acid formula | KOH | SeCl_4 | H_2O | KCl | H_2SeO_3 Hill formula | HKO | Cl_4Se | H_2O | ClK | H_2O_3Se name | potassium hydroxide | selenium tetrachloride | water | potassium chloride | selenious acid IUPAC name | potassium hydroxide | | water | potassium chloride | selenous acid
Substance properties
| potassium hydroxide | selenium tetrachloride | water | potassium chloride | selenious acid molar mass | 56.105 g/mol | 220.8 g/mol | 18.015 g/mol | 74.55 g/mol | 128.98 g/mol phase | solid (at STP) | solid (at STP) | liquid (at STP) | solid (at STP) | solid (at STP) melting point | 406 °C | 330 °C | 0 °C | 770 °C | 70 °C boiling point | 1327 °C | | 99.9839 °C | 1420 °C | 315 °C density | 2.044 g/cm^3 | 2.6 g/cm^3 | 1 g/cm^3 | 1.98 g/cm^3 | 3.004 g/cm^3 solubility in water | soluble | | | soluble | surface tension | | | 0.0728 N/m | | dynamic viscosity | 0.001 Pa s (at 550 °C) | | 8.9×10^-4 Pa s (at 25 °C) | | odor | | | odorless | odorless |
Units