AgNO2 + BaBr = AgBr + BaNO2

AgNO_2 silver nitrite + BaBr ⟶ AgBr silver bromide + BaNO2

Balance the chemical equation algebraically: AgNO_2 + BaBr ⟶ AgBr + BaNO2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 AgNO_2 + c_2 BaBr ⟶ c_3 AgBr + c_4 BaNO2 Set the number of atoms in the reactants equal to the number of atoms in the products for Ag, N, O, Ba and Br: Ag: | c_1 = c_3 N: | c_1 = c_4 O: | 2 c_1 = 2 c_4 Ba: | c_2 = c_4 Br: | c_2 = c_3 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: | | AgNO_2 + BaBr ⟶ AgBr + BaNO2

+ BaBr ⟶ + BaNO2

silver nitrite + BaBr ⟶ silver bromide + BaNO2

Construct the equilibrium constant, K, expression for: AgNO_2 + BaBr ⟶ AgBr + BaNO2 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: AgNO_2 + BaBr ⟶ AgBr + BaNO2 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 AgNO_2 | 1 | -1 BaBr | 1 | -1 AgBr | 1 | 1 BaNO2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression AgNO_2 | 1 | -1 | ([AgNO2])^(-1) BaBr | 1 | -1 | ([BaBr])^(-1) AgBr | 1 | 1 | [AgBr] BaNO2 | 1 | 1 | [BaNO2] 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 = ([AgNO2])^(-1) ([BaBr])^(-1) [AgBr] [BaNO2] = ([AgBr] [BaNO2])/([AgNO2] [BaBr])

Construct the rate of reaction expression for: AgNO_2 + BaBr ⟶ AgBr + BaNO2 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: AgNO_2 + BaBr ⟶ AgBr + BaNO2 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 AgNO_2 | 1 | -1 BaBr | 1 | -1 AgBr | 1 | 1 BaNO2 | 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 AgNO_2 | 1 | -1 | -(Δ[AgNO2])/(Δt) BaBr | 1 | -1 | -(Δ[BaBr])/(Δt) AgBr | 1 | 1 | (Δ[AgBr])/(Δt) BaNO2 | 1 | 1 | (Δ[BaNO2])/(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[AgNO2])/(Δt) = -(Δ[BaBr])/(Δt) = (Δ[AgBr])/(Δt) = (Δ[BaNO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| silver nitrite | BaBr | silver bromide | BaNO2 formula | AgNO_2 | BaBr | AgBr | BaNO2 name | silver nitrite | | silver bromide | IUPAC name | silver nitrite | | bromosilver |

| silver nitrite | BaBr | silver bromide | BaNO2 molar mass | 153.873 g/mol | 217.23 g/mol | 187.77 g/mol | 183.33 g/mol phase | solid (at STP) | | solid (at STP) | melting point | 140 °C | | 432 °C | boiling point | | | 1300 °C | density | 4.453 g/cm^3 | | 6.473 g/cm^3 | solubility in water | | | insoluble |