HNO3 + SnS = H2O + H2SO4 + NO2 + H2SnO3

HNO_3 nitric acid + SnS tin(II) sulfide ⟶ H_2O water + H_2SO_4 sulfuric acid + NO_2 nitrogen dioxide + H2SnO3

Balance the chemical equation algebraically: HNO_3 + SnS ⟶ H_2O + H_2SO_4 + NO_2 + H2SnO3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HNO_3 + c_2 SnS ⟶ c_3 H_2O + c_4 H_2SO_4 + c_5 NO_2 + c_6 H2SnO3 Set the number of atoms in the reactants equal to the number of atoms in the products for H, N, O, S and Sn: H: | c_1 = 2 c_3 + 2 c_4 + 2 c_6 N: | c_1 = c_5 O: | 3 c_1 = c_3 + 4 c_4 + 2 c_5 + 3 c_6 S: | c_2 = c_4 Sn: | c_2 = 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 10 c_2 = 1 c_3 = 3 c_4 = 1 c_5 = 10 c_6 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 10 HNO_3 + SnS ⟶ 3 H_2O + H_2SO_4 + 10 NO_2 + H2SnO3

+ ⟶ + + + H2SnO3

nitric acid + tin(II) sulfide ⟶ water + sulfuric acid + nitrogen dioxide + H2SnO3

Construct the equilibrium constant, K, expression for: HNO_3 + SnS ⟶ H_2O + H_2SO_4 + NO_2 + H2SnO3 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: 10 HNO_3 + SnS ⟶ 3 H_2O + H_2SO_4 + 10 NO_2 + H2SnO3 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 HNO_3 | 10 | -10 SnS | 1 | -1 H_2O | 3 | 3 H_2SO_4 | 1 | 1 NO_2 | 10 | 10 H2SnO3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HNO_3 | 10 | -10 | ([HNO3])^(-10) SnS | 1 | -1 | ([SnS])^(-1) H_2O | 3 | 3 | ([H2O])^3 H_2SO_4 | 1 | 1 | [H2SO4] NO_2 | 10 | 10 | ([NO2])^10 H2SnO3 | 1 | 1 | [H2SnO3] 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 = ([HNO3])^(-10) ([SnS])^(-1) ([H2O])^3 [H2SO4] ([NO2])^10 [H2SnO3] = (([H2O])^3 [H2SO4] ([NO2])^10 [H2SnO3])/(([HNO3])^10 [SnS])

Construct the rate of reaction expression for: HNO_3 + SnS ⟶ H_2O + H_2SO_4 + NO_2 + H2SnO3 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: 10 HNO_3 + SnS ⟶ 3 H_2O + H_2SO_4 + 10 NO_2 + H2SnO3 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 HNO_3 | 10 | -10 SnS | 1 | -1 H_2O | 3 | 3 H_2SO_4 | 1 | 1 NO_2 | 10 | 10 H2SnO3 | 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 HNO_3 | 10 | -10 | -1/10 (Δ[HNO3])/(Δt) SnS | 1 | -1 | -(Δ[SnS])/(Δt) H_2O | 3 | 3 | 1/3 (Δ[H2O])/(Δt) H_2SO_4 | 1 | 1 | (Δ[H2SO4])/(Δt) NO_2 | 10 | 10 | 1/10 (Δ[NO2])/(Δt) H2SnO3 | 1 | 1 | (Δ[H2SnO3])/(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 = -1/10 (Δ[HNO3])/(Δt) = -(Δ[SnS])/(Δt) = 1/3 (Δ[H2O])/(Δt) = (Δ[H2SO4])/(Δt) = 1/10 (Δ[NO2])/(Δt) = (Δ[H2SnO3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| nitric acid | tin(II) sulfide | water | sulfuric acid | nitrogen dioxide | H2SnO3 formula | HNO_3 | SnS | H_2O | H_2SO_4 | NO_2 | H2SnO3 Hill formula | HNO_3 | SSn | H_2O | H_2O_4S | NO_2 | H2O3Sn name | nitric acid | tin(II) sulfide | water | sulfuric acid | nitrogen dioxide | IUPAC name | nitric acid | thioxotin | water | sulfuric acid | Nitrogen dioxide |

| nitric acid | tin(II) sulfide | water | sulfuric acid | nitrogen dioxide | H2SnO3 molar mass | 63.012 g/mol | 150.77 g/mol | 18.015 g/mol | 98.07 g/mol | 46.005 g/mol | 168.72 g/mol phase | liquid (at STP) | | liquid (at STP) | liquid (at STP) | gas (at STP) | melting point | -41.6 °C | | 0 °C | 10.371 °C | -11 °C | boiling point | 83 °C | | 99.9839 °C | 279.6 °C | 21 °C | density | 1.5129 g/cm^3 | 5.22 g/cm^3 | 1 g/cm^3 | 1.8305 g/cm^3 | 0.00188 g/cm^3 (at 25 °C) | solubility in water | miscible | | | very soluble | reacts | surface tension | | | 0.0728 N/m | 0.0735 N/m | | dynamic viscosity | 7.6×10^-4 Pa s (at 25 °C) | | 8.9×10^-4 Pa s (at 25 °C) | 0.021 Pa s (at 25 °C) | 4.02×10^-4 Pa s (at 25 °C) | odor | | | odorless | odorless | |