Input interpretation
O_2 oxygen + NaOH sodium hydroxide + Mn(NO_3)_2 manganese(II) nitrate ⟶ H_2O water + MnO_2 manganese dioxide + NaNO_3 sodium nitrate
Balanced equation
Balance the chemical equation algebraically: O_2 + NaOH + Mn(NO_3)_2 ⟶ H_2O + MnO_2 + NaNO_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 O_2 + c_2 NaOH + c_3 Mn(NO_3)_2 ⟶ c_4 H_2O + c_5 MnO_2 + c_6 NaNO_3 Set the number of atoms in the reactants equal to the number of atoms in the products for O, H, Na, Mn and N: O: | 2 c_1 + c_2 + 6 c_3 = c_4 + 2 c_5 + 3 c_6 H: | c_2 = 2 c_4 Na: | c_2 = c_6 Mn: | c_3 = c_5 N: | 2 c_3 = 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 4 c_3 = 2 c_4 = 2 c_5 = 2 c_6 = 4 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | O_2 + 4 NaOH + 2 Mn(NO_3)_2 ⟶ 2 H_2O + 2 MnO_2 + 4 NaNO_3
Structures
+ + ⟶ + +
Names
oxygen + sodium hydroxide + manganese(II) nitrate ⟶ water + manganese dioxide + sodium nitrate
Equilibrium constant
Construct the equilibrium constant, K, expression for: O_2 + NaOH + Mn(NO_3)_2 ⟶ H_2O + MnO_2 + NaNO_3 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: O_2 + 4 NaOH + 2 Mn(NO_3)_2 ⟶ 2 H_2O + 2 MnO_2 + 4 NaNO_3 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 O_2 | 1 | -1 NaOH | 4 | -4 Mn(NO_3)_2 | 2 | -2 H_2O | 2 | 2 MnO_2 | 2 | 2 NaNO_3 | 4 | 4 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression O_2 | 1 | -1 | ([O2])^(-1) NaOH | 4 | -4 | ([NaOH])^(-4) Mn(NO_3)_2 | 2 | -2 | ([Mn(NO3)2])^(-2) H_2O | 2 | 2 | ([H2O])^2 MnO_2 | 2 | 2 | ([MnO2])^2 NaNO_3 | 4 | 4 | ([NaNO3])^4 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 = ([O2])^(-1) ([NaOH])^(-4) ([Mn(NO3)2])^(-2) ([H2O])^2 ([MnO2])^2 ([NaNO3])^4 = (([H2O])^2 ([MnO2])^2 ([NaNO3])^4)/([O2] ([NaOH])^4 ([Mn(NO3)2])^2)
Rate of reaction
Construct the rate of reaction expression for: O_2 + NaOH + Mn(NO_3)_2 ⟶ H_2O + MnO_2 + NaNO_3 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: O_2 + 4 NaOH + 2 Mn(NO_3)_2 ⟶ 2 H_2O + 2 MnO_2 + 4 NaNO_3 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 O_2 | 1 | -1 NaOH | 4 | -4 Mn(NO_3)_2 | 2 | -2 H_2O | 2 | 2 MnO_2 | 2 | 2 NaNO_3 | 4 | 4 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 O_2 | 1 | -1 | -(Δ[O2])/(Δt) NaOH | 4 | -4 | -1/4 (Δ[NaOH])/(Δt) Mn(NO_3)_2 | 2 | -2 | -1/2 (Δ[Mn(NO3)2])/(Δt) H_2O | 2 | 2 | 1/2 (Δ[H2O])/(Δt) MnO_2 | 2 | 2 | 1/2 (Δ[MnO2])/(Δt) NaNO_3 | 4 | 4 | 1/4 (Δ[NaNO3])/(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[O2])/(Δt) = -1/4 (Δ[NaOH])/(Δt) = -1/2 (Δ[Mn(NO3)2])/(Δt) = 1/2 (Δ[H2O])/(Δt) = 1/2 (Δ[MnO2])/(Δt) = 1/4 (Δ[NaNO3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| oxygen | sodium hydroxide | manganese(II) nitrate | water | manganese dioxide | sodium nitrate formula | O_2 | NaOH | Mn(NO_3)_2 | H_2O | MnO_2 | NaNO_3 Hill formula | O_2 | HNaO | MnN_2O_6 | H_2O | MnO_2 | NNaO_3 name | oxygen | sodium hydroxide | manganese(II) nitrate | water | manganese dioxide | sodium nitrate IUPAC name | molecular oxygen | sodium hydroxide | manganese(2+) dinitrate | water | dioxomanganese | sodium nitrate
Substance properties
| oxygen | sodium hydroxide | manganese(II) nitrate | water | manganese dioxide | sodium nitrate molar mass | 31.998 g/mol | 39.997 g/mol | 178.95 g/mol | 18.015 g/mol | 86.936 g/mol | 84.994 g/mol phase | gas (at STP) | solid (at STP) | | liquid (at STP) | solid (at STP) | solid (at STP) melting point | -218 °C | 323 °C | | 0 °C | 535 °C | 306 °C boiling point | -183 °C | 1390 °C | | 99.9839 °C | | density | 0.001429 g/cm^3 (at 0 °C) | 2.13 g/cm^3 | 1.536 g/cm^3 | 1 g/cm^3 | 5.03 g/cm^3 | 2.26 g/cm^3 solubility in water | | soluble | | | insoluble | soluble surface tension | 0.01347 N/m | 0.07435 N/m | | 0.0728 N/m | | dynamic viscosity | 2.055×10^-5 Pa s (at 25 °C) | 0.004 Pa s (at 350 °C) | | 8.9×10^-4 Pa s (at 25 °C) | | 0.003 Pa s (at 250 °C) odor | odorless | | | odorless | |
Units