CaCO3 + SO3 = CO2 + CaSO4

CaCO_3 calcium carbonate + SO_3 sulfur trioxide ⟶ CO_2 carbon dioxide + CaSO_4 calcium sulfate

Balance the chemical equation algebraically: CaCO_3 + SO_3 ⟶ CO_2 + CaSO_4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 CaCO_3 + c_2 SO_3 ⟶ c_3 CO_2 + c_4 CaSO_4 Set the number of atoms in the reactants equal to the number of atoms in the products for C, Ca, O and S: C: | c_1 = c_3 Ca: | c_1 = c_4 O: | 3 c_1 + 3 c_2 = 2 c_3 + 4 c_4 S: | 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 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | CaCO_3 + SO_3 ⟶ CO_2 + CaSO_4

+ ⟶ +

calcium carbonate + sulfur trioxide ⟶ carbon dioxide + calcium sulfate

Construct the equilibrium constant, K, expression for: CaCO_3 + SO_3 ⟶ CO_2 + CaSO_4 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: CaCO_3 + SO_3 ⟶ CO_2 + CaSO_4 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 CaCO_3 | 1 | -1 SO_3 | 1 | -1 CO_2 | 1 | 1 CaSO_4 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression CaCO_3 | 1 | -1 | ([CaCO3])^(-1) SO_3 | 1 | -1 | ([SO3])^(-1) CO_2 | 1 | 1 | [CO2] CaSO_4 | 1 | 1 | [CaSO4] 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 = ([CaCO3])^(-1) ([SO3])^(-1) [CO2] [CaSO4] = ([CO2] [CaSO4])/([CaCO3] [SO3])

Construct the rate of reaction expression for: CaCO_3 + SO_3 ⟶ CO_2 + CaSO_4 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: CaCO_3 + SO_3 ⟶ CO_2 + CaSO_4 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 CaCO_3 | 1 | -1 SO_3 | 1 | -1 CO_2 | 1 | 1 CaSO_4 | 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 CaCO_3 | 1 | -1 | -(Δ[CaCO3])/(Δt) SO_3 | 1 | -1 | -(Δ[SO3])/(Δt) CO_2 | 1 | 1 | (Δ[CO2])/(Δt) CaSO_4 | 1 | 1 | (Δ[CaSO4])/(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[CaCO3])/(Δt) = -(Δ[SO3])/(Δt) = (Δ[CO2])/(Δt) = (Δ[CaSO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| calcium carbonate | sulfur trioxide | carbon dioxide | calcium sulfate formula | CaCO_3 | SO_3 | CO_2 | CaSO_4 Hill formula | CCaO_3 | O_3S | CO_2 | CaO_4S name | calcium carbonate | sulfur trioxide | carbon dioxide | calcium sulfate

| calcium carbonate | sulfur trioxide | carbon dioxide | calcium sulfate molar mass | 100.09 g/mol | 80.06 g/mol | 44.009 g/mol | 136.13 g/mol phase | solid (at STP) | liquid (at STP) | gas (at STP) | melting point | 1340 °C | 16.8 °C | -56.56 °C (at triple point) | boiling point | | 44.7 °C | -78.5 °C (at sublimation point) | density | 2.71 g/cm^3 | 1.97 g/cm^3 | 0.00184212 g/cm^3 (at 20 °C) | solubility in water | insoluble | reacts | | slightly soluble dynamic viscosity | | 0.00159 Pa s (at 30 °C) | 1.491×10^-5 Pa s (at 25 °C) | odor | | | odorless | odorless