Input interpretation
Zn zinc + CH_3CO_2H acetic acid ⟶ H_2 hydrogen + (CH3COO)2Zn
Balanced equation
Balance the chemical equation algebraically: Zn + CH_3CO_2H ⟶ H_2 + (CH3COO)2Zn Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Zn + c_2 CH_3CO_2H ⟶ c_3 H_2 + c_4 (CH3COO)2Zn Set the number of atoms in the reactants equal to the number of atoms in the products for Zn, C, H and O: Zn: | c_1 = c_4 C: | 2 c_2 = 4 c_4 H: | 4 c_2 = 2 c_3 + 6 c_4 O: | 2 c_2 = 4 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 = 2 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Zn + 2 CH_3CO_2H ⟶ H_2 + (CH3COO)2Zn
Structures
+ ⟶ + (CH3COO)2Zn
Names
zinc + acetic acid ⟶ hydrogen + (CH3COO)2Zn
Equilibrium constant
Construct the equilibrium constant, K, expression for: Zn + CH_3CO_2H ⟶ H_2 + (CH3COO)2Zn 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: Zn + 2 CH_3CO_2H ⟶ H_2 + (CH3COO)2Zn 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 Zn | 1 | -1 CH_3CO_2H | 2 | -2 H_2 | 1 | 1 (CH3COO)2Zn | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Zn | 1 | -1 | ([Zn])^(-1) CH_3CO_2H | 2 | -2 | ([CH3CO2H])^(-2) H_2 | 1 | 1 | [H2] (CH3COO)2Zn | 1 | 1 | [(CH3COO)2Zn] 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 = ([Zn])^(-1) ([CH3CO2H])^(-2) [H2] [(CH3COO)2Zn] = ([H2] [(CH3COO)2Zn])/([Zn] ([CH3CO2H])^2)
Rate of reaction
Construct the rate of reaction expression for: Zn + CH_3CO_2H ⟶ H_2 + (CH3COO)2Zn 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: Zn + 2 CH_3CO_2H ⟶ H_2 + (CH3COO)2Zn 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 Zn | 1 | -1 CH_3CO_2H | 2 | -2 H_2 | 1 | 1 (CH3COO)2Zn | 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 Zn | 1 | -1 | -(Δ[Zn])/(Δt) CH_3CO_2H | 2 | -2 | -1/2 (Δ[CH3CO2H])/(Δt) H_2 | 1 | 1 | (Δ[H2])/(Δt) (CH3COO)2Zn | 1 | 1 | (Δ[(CH3COO)2Zn])/(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[Zn])/(Δt) = -1/2 (Δ[CH3CO2H])/(Δt) = (Δ[H2])/(Δt) = (Δ[(CH3COO)2Zn])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| zinc | acetic acid | hydrogen | (CH3COO)2Zn formula | Zn | CH_3CO_2H | H_2 | (CH3COO)2Zn Hill formula | Zn | C_2H_4O_2 | H_2 | C4H6O4Zn name | zinc | acetic acid | hydrogen | IUPAC name | zinc | acetic acid | molecular hydrogen |
Substance properties
| zinc | acetic acid | hydrogen | (CH3COO)2Zn molar mass | 65.38 g/mol | 60.052 g/mol | 2.016 g/mol | 183.5 g/mol phase | solid (at STP) | liquid (at STP) | gas (at STP) | melting point | 420 °C | 16.2 °C | -259.2 °C | boiling point | 907 °C | 117.5 °C | -252.8 °C | density | 7.14 g/cm^3 | 1.049 g/cm^3 | 8.99×10^-5 g/cm^3 (at 0 °C) | solubility in water | insoluble | miscible | | surface tension | | 0.0288 N/m | | dynamic viscosity | | 0.001056 Pa s (at 25 °C) | 8.9×10^-6 Pa s (at 25 °C) | odor | odorless | vinegar-like | odorless |
Units