Input interpretation
KNO_3 potassium nitrate + PbCO_3 cerussete ⟶ CO_2 carbon dioxide + KNO_2 potassium nitrite + PbO4
Balanced equation
Balance the chemical equation algebraically: KNO_3 + PbCO_3 ⟶ CO_2 + KNO_2 + PbO4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 KNO_3 + c_2 PbCO_3 ⟶ c_3 CO_2 + c_4 KNO_2 + c_5 PbO4 Set the number of atoms in the reactants equal to the number of atoms in the products for K, N, O, C and Pb: K: | c_1 = c_4 N: | c_1 = c_4 O: | 3 c_1 + 3 c_2 = 2 c_3 + 2 c_4 + 4 c_5 C: | c_2 = c_3 Pb: | 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 = 3 c_2 = 1 c_3 = 1 c_4 = 3 c_5 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 KNO_3 + PbCO_3 ⟶ CO_2 + 3 KNO_2 + PbO4
Structures
+ ⟶ + + PbO4
Names
potassium nitrate + cerussete ⟶ carbon dioxide + potassium nitrite + PbO4
Equilibrium constant
Construct the equilibrium constant, K, expression for: KNO_3 + PbCO_3 ⟶ CO_2 + KNO_2 + PbO4 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: 3 KNO_3 + PbCO_3 ⟶ CO_2 + 3 KNO_2 + PbO4 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 KNO_3 | 3 | -3 PbCO_3 | 1 | -1 CO_2 | 1 | 1 KNO_2 | 3 | 3 PbO4 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression KNO_3 | 3 | -3 | ([KNO3])^(-3) PbCO_3 | 1 | -1 | ([PbCO3])^(-1) CO_2 | 1 | 1 | [CO2] KNO_2 | 3 | 3 | ([KNO2])^3 PbO4 | 1 | 1 | [PbO4] 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 = ([KNO3])^(-3) ([PbCO3])^(-1) [CO2] ([KNO2])^3 [PbO4] = ([CO2] ([KNO2])^3 [PbO4])/(([KNO3])^3 [PbCO3])
Rate of reaction
Construct the rate of reaction expression for: KNO_3 + PbCO_3 ⟶ CO_2 + KNO_2 + PbO4 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: 3 KNO_3 + PbCO_3 ⟶ CO_2 + 3 KNO_2 + PbO4 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 KNO_3 | 3 | -3 PbCO_3 | 1 | -1 CO_2 | 1 | 1 KNO_2 | 3 | 3 PbO4 | 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 KNO_3 | 3 | -3 | -1/3 (Δ[KNO3])/(Δt) PbCO_3 | 1 | -1 | -(Δ[PbCO3])/(Δt) CO_2 | 1 | 1 | (Δ[CO2])/(Δt) KNO_2 | 3 | 3 | 1/3 (Δ[KNO2])/(Δt) PbO4 | 1 | 1 | (Δ[PbO4])/(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 = -1/3 (Δ[KNO3])/(Δt) = -(Δ[PbCO3])/(Δt) = (Δ[CO2])/(Δt) = 1/3 (Δ[KNO2])/(Δt) = (Δ[PbO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| potassium nitrate | cerussete | carbon dioxide | potassium nitrite | PbO4 formula | KNO_3 | PbCO_3 | CO_2 | KNO_2 | PbO4 Hill formula | KNO_3 | CO_3Pb | CO_2 | KNO_2 | O4Pb name | potassium nitrate | cerussete | carbon dioxide | potassium nitrite | IUPAC name | potassium nitrate | lead(+2) cation carbonate | carbon dioxide | potassium nitrite |
Substance properties
| potassium nitrate | cerussete | carbon dioxide | potassium nitrite | PbO4 molar mass | 101.1 g/mol | 267.2 g/mol | 44.009 g/mol | 85.103 g/mol | 271.2 g/mol phase | solid (at STP) | | gas (at STP) | solid (at STP) | melting point | 334 °C | | -56.56 °C (at triple point) | 350 °C | boiling point | | | -78.5 °C (at sublimation point) | | density | | 6.43 g/cm^3 | 0.00184212 g/cm^3 (at 20 °C) | 1.915 g/cm^3 | solubility in water | soluble | insoluble | | | dynamic viscosity | | | 1.491×10^-5 Pa s (at 25 °C) | | odor | odorless | | odorless | |
Units