O2 + NiS = SO2 + NiO

O_2 oxygen + SNi nickel(II) sulfide ⟶ SO_2 sulfur dioxide + NiO nickel monoxide

Balance the chemical equation algebraically: O_2 + SNi ⟶ SO_2 + NiO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 O_2 + c_2 SNi ⟶ c_3 SO_2 + c_4 NiO Set the number of atoms in the reactants equal to the number of atoms in the products for O, Ni and S: O: | 2 c_1 = 2 c_3 + c_4 Ni: | c_2 = c_4 S: | c_2 = c_3 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 = 3/2 c_2 = 1 c_3 = 1 c_4 = 1 Multiply by the least common denominator, 2, to eliminate fractional coefficients: c_1 = 3 c_2 = 2 c_3 = 2 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 O_2 + 2 SNi ⟶ 2 SO_2 + 2 NiO

+ ⟶ +

oxygen + nickel(II) sulfide ⟶ sulfur dioxide + nickel monoxide

Construct the equilibrium constant, K, expression for: O_2 + SNi ⟶ SO_2 + NiO 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: 3 O_2 + 2 SNi ⟶ 2 SO_2 + 2 NiO 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 | 3 | -3 SNi | 2 | -2 SO_2 | 2 | 2 NiO | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression O_2 | 3 | -3 | ([O2])^(-3) SNi | 2 | -2 | ([S1Ni1])^(-2) SO_2 | 2 | 2 | ([SO2])^2 NiO | 2 | 2 | ([NiO])^2 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])^(-3) ([S1Ni1])^(-2) ([SO2])^2 ([NiO])^2 = (([SO2])^2 ([NiO])^2)/(([O2])^3 ([S1Ni1])^2)

Construct the rate of reaction expression for: O_2 + SNi ⟶ SO_2 + NiO 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: 3 O_2 + 2 SNi ⟶ 2 SO_2 + 2 NiO 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 | 3 | -3 SNi | 2 | -2 SO_2 | 2 | 2 NiO | 2 | 2 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 | 3 | -3 | -1/3 (Δ[O2])/(Δt) SNi | 2 | -2 | -1/2 (Δ[S1Ni1])/(Δt) SO_2 | 2 | 2 | 1/2 (Δ[SO2])/(Δt) NiO | 2 | 2 | 1/2 (Δ[NiO])/(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 = -1/3 (Δ[O2])/(Δt) = -1/2 (Δ[S1Ni1])/(Δt) = 1/2 (Δ[SO2])/(Δt) = 1/2 (Δ[NiO])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| oxygen | nickel(II) sulfide | sulfur dioxide | nickel monoxide formula | O_2 | SNi | SO_2 | NiO Hill formula | O_2 | NiS | O_2S | NiO name | oxygen | nickel(II) sulfide | sulfur dioxide | nickel monoxide IUPAC name | molecular oxygen | sulfanylidenenickel | sulfur dioxide | oxonickel

| oxygen | nickel(II) sulfide | sulfur dioxide | nickel monoxide molar mass | 31.998 g/mol | 90.75 g/mol | 64.06 g/mol | 74.692 g/mol phase | gas (at STP) | | gas (at STP) | solid (at STP) melting point | -218 °C | | -73 °C | 1955 °C boiling point | -183 °C | | -10 °C | density | 0.001429 g/cm^3 (at 0 °C) | | 0.002619 g/cm^3 (at 25 °C) | 6.67 g/cm^3 solubility in water | | | | insoluble surface tension | 0.01347 N/m | | 0.02859 N/m | dynamic viscosity | 2.055×10^-5 Pa s (at 25 °C) | | 1.282×10^-5 Pa s (at 25 °C) | odor | odorless | | |