Input interpretation
HNO_3 nitric acid + C_6H_5NO_2 nitrobenzene ⟶ H_2O water + CO_2 carbon dioxide + N_2 nitrogen
Balanced equation
Balance the chemical equation algebraically: HNO_3 + C_6H_5NO_2 ⟶ H_2O + CO_2 + N_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HNO_3 + c_2 C_6H_5NO_2 ⟶ c_3 H_2O + c_4 CO_2 + c_5 N_2 Set the number of atoms in the reactants equal to the number of atoms in the products for H, N, O and C: H: | c_1 + 5 c_2 = 2 c_3 N: | c_1 + c_2 = 2 c_5 O: | 3 c_1 + 2 c_2 = c_3 + 2 c_4 C: | 6 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 5 c_2 = 1 c_3 = 5 c_4 = 6 c_5 = 3 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 5 HNO_3 + C_6H_5NO_2 ⟶ 5 H_2O + 6 CO_2 + 3 N_2
Structures
+ ⟶ + +
Names
nitric acid + nitrobenzene ⟶ water + carbon dioxide + nitrogen
Equilibrium constant
Construct the equilibrium constant, K, expression for: HNO_3 + C_6H_5NO_2 ⟶ H_2O + CO_2 + N_2 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: 5 HNO_3 + C_6H_5NO_2 ⟶ 5 H_2O + 6 CO_2 + 3 N_2 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 | 5 | -5 C_6H_5NO_2 | 1 | -1 H_2O | 5 | 5 CO_2 | 6 | 6 N_2 | 3 | 3 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HNO_3 | 5 | -5 | ([HNO3])^(-5) C_6H_5NO_2 | 1 | -1 | ([C6H5NO2])^(-1) H_2O | 5 | 5 | ([H2O])^5 CO_2 | 6 | 6 | ([CO2])^6 N_2 | 3 | 3 | ([N2])^3 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])^(-5) ([C6H5NO2])^(-1) ([H2O])^5 ([CO2])^6 ([N2])^3 = (([H2O])^5 ([CO2])^6 ([N2])^3)/(([HNO3])^5 [C6H5NO2])
Rate of reaction
Construct the rate of reaction expression for: HNO_3 + C_6H_5NO_2 ⟶ H_2O + CO_2 + N_2 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: 5 HNO_3 + C_6H_5NO_2 ⟶ 5 H_2O + 6 CO_2 + 3 N_2 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 | 5 | -5 C_6H_5NO_2 | 1 | -1 H_2O | 5 | 5 CO_2 | 6 | 6 N_2 | 3 | 3 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 | 5 | -5 | -1/5 (Δ[HNO3])/(Δt) C_6H_5NO_2 | 1 | -1 | -(Δ[C6H5NO2])/(Δt) H_2O | 5 | 5 | 1/5 (Δ[H2O])/(Δt) CO_2 | 6 | 6 | 1/6 (Δ[CO2])/(Δt) N_2 | 3 | 3 | 1/3 (Δ[N2])/(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 = -1/5 (Δ[HNO3])/(Δt) = -(Δ[C6H5NO2])/(Δt) = 1/5 (Δ[H2O])/(Δt) = 1/6 (Δ[CO2])/(Δt) = 1/3 (Δ[N2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| nitric acid | nitrobenzene | water | carbon dioxide | nitrogen formula | HNO_3 | C_6H_5NO_2 | H_2O | CO_2 | N_2 name | nitric acid | nitrobenzene | water | carbon dioxide | nitrogen IUPAC name | nitric acid | nitrobenzene | water | carbon dioxide | molecular nitrogen