Input interpretation
Cu(OH)_2 copper hydroxide + NH_2NH_2 diazane ⟶ H_2O water + Cu copper + N_2 nitrogen
Balanced equation
Balance the chemical equation algebraically: Cu(OH)_2 + NH_2NH_2 ⟶ H_2O + Cu + N_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Cu(OH)_2 + c_2 NH_2NH_2 ⟶ c_3 H_2O + c_4 Cu + c_5 N_2 Set the number of atoms in the reactants equal to the number of atoms in the products for Cu, H, O and N: Cu: | c_1 = c_4 H: | 2 c_1 + 4 c_2 = 2 c_3 O: | 2 c_1 = c_3 N: | 2 c_2 = 2 c_5 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 = 2 c_2 = 1 c_3 = 4 c_4 = 2 c_5 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 Cu(OH)_2 + NH_2NH_2 ⟶ 4 H_2O + 2 Cu + N_2
Structures
+ ⟶ + +
Names
copper hydroxide + diazane ⟶ water + copper + nitrogen
Equilibrium constant
Construct the equilibrium constant, K, expression for: Cu(OH)_2 + NH_2NH_2 ⟶ H_2O + Cu + 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: 2 Cu(OH)_2 + NH_2NH_2 ⟶ 4 H_2O + 2 Cu + 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 Cu(OH)_2 | 2 | -2 NH_2NH_2 | 1 | -1 H_2O | 4 | 4 Cu | 2 | 2 N_2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Cu(OH)_2 | 2 | -2 | ([Cu(OH)2])^(-2) NH_2NH_2 | 1 | -1 | ([NH2NH2])^(-1) H_2O | 4 | 4 | ([H2O])^4 Cu | 2 | 2 | ([Cu])^2 N_2 | 1 | 1 | [N2] 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 = ([Cu(OH)2])^(-2) ([NH2NH2])^(-1) ([H2O])^4 ([Cu])^2 [N2] = (([H2O])^4 ([Cu])^2 [N2])/(([Cu(OH)2])^2 [NH2NH2])
Rate of reaction
Construct the rate of reaction expression for: Cu(OH)_2 + NH_2NH_2 ⟶ H_2O + Cu + 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: 2 Cu(OH)_2 + NH_2NH_2 ⟶ 4 H_2O + 2 Cu + 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 Cu(OH)_2 | 2 | -2 NH_2NH_2 | 1 | -1 H_2O | 4 | 4 Cu | 2 | 2 N_2 | 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 Cu(OH)_2 | 2 | -2 | -1/2 (Δ[Cu(OH)2])/(Δt) NH_2NH_2 | 1 | -1 | -(Δ[NH2NH2])/(Δt) H_2O | 4 | 4 | 1/4 (Δ[H2O])/(Δt) Cu | 2 | 2 | 1/2 (Δ[Cu])/(Δt) N_2 | 1 | 1 | (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 = -1/2 (Δ[Cu(OH)2])/(Δt) = -(Δ[NH2NH2])/(Δt) = 1/4 (Δ[H2O])/(Δt) = 1/2 (Δ[Cu])/(Δt) = (Δ[N2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| copper hydroxide | diazane | water | copper | nitrogen formula | Cu(OH)_2 | NH_2NH_2 | H_2O | Cu | N_2 Hill formula | CuH_2O_2 | H_4N_2 | H_2O | Cu | N_2 name | copper hydroxide | diazane | water | copper | nitrogen IUPAC name | copper dihydroxide | hydrazine | water | copper | molecular nitrogen
Substance properties
| copper hydroxide | diazane | water | copper | nitrogen molar mass | 97.56 g/mol | 32.046 g/mol | 18.015 g/mol | 63.546 g/mol | 28.014 g/mol phase | | liquid (at STP) | liquid (at STP) | solid (at STP) | gas (at STP) melting point | | 1 °C | 0 °C | 1083 °C | -210 °C boiling point | | 113.5 °C | 99.9839 °C | 2567 °C | -195.79 °C density | | 1.011 g/cm^3 | 1 g/cm^3 | 8.96 g/cm^3 | 0.001251 g/cm^3 (at 0 °C) solubility in water | | miscible | | insoluble | insoluble surface tension | | 0.0667 N/m | 0.0728 N/m | | 0.0066 N/m dynamic viscosity | | 8.76×10^-4 Pa s (at 25 °C) | 8.9×10^-4 Pa s (at 25 °C) | | 1.78×10^-5 Pa s (at 25 °C) odor | | | odorless | odorless | odorless
Units