K2S + Ni(NO3)2 = KNO3 + NiS

K2S + Ni(NO_3)_2 nickel(II) nitrate ⟶ KNO_3 potassium nitrate + SNi nickel(II) sulfide

Balance the chemical equation algebraically: K2S + Ni(NO_3)_2 ⟶ KNO_3 + SNi Add stoichiometric coefficients, c_i, to the reactants and products: c_1 K2S + c_2 Ni(NO_3)_2 ⟶ c_3 KNO_3 + c_4 SNi Set the number of atoms in the reactants equal to the number of atoms in the products for K, S, N, Ni and O: K: | 2 c_1 = c_3 S: | c_1 = c_4 N: | 2 c_2 = c_3 Ni: | c_2 = c_4 O: | 6 c_2 = 3 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 1 c_3 = 2 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | K2S + Ni(NO_3)_2 ⟶ 2 KNO_3 + SNi

K2S + ⟶ +

K2S + nickel(II) nitrate ⟶ potassium nitrate + nickel(II) sulfide

Construct the equilibrium constant, K, expression for: K2S + Ni(NO_3)_2 ⟶ KNO_3 + SNi 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: K2S + Ni(NO_3)_2 ⟶ 2 KNO_3 + SNi 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 K2S | 1 | -1 Ni(NO_3)_2 | 1 | -1 KNO_3 | 2 | 2 SNi | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression K2S | 1 | -1 | ([K2S])^(-1) Ni(NO_3)_2 | 1 | -1 | ([Ni(NO3)2])^(-1) KNO_3 | 2 | 2 | ([KNO3])^2 SNi | 1 | 1 | [S1Ni1] 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 = ([K2S])^(-1) ([Ni(NO3)2])^(-1) ([KNO3])^2 [S1Ni1] = (([KNO3])^2 [S1Ni1])/([K2S] [Ni(NO3)2])

Construct the rate of reaction expression for: K2S + Ni(NO_3)_2 ⟶ KNO_3 + SNi 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: K2S + Ni(NO_3)_2 ⟶ 2 KNO_3 + SNi 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 K2S | 1 | -1 Ni(NO_3)_2 | 1 | -1 KNO_3 | 2 | 2 SNi | 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 K2S | 1 | -1 | -(Δ[K2S])/(Δt) Ni(NO_3)_2 | 1 | -1 | -(Δ[Ni(NO3)2])/(Δt) KNO_3 | 2 | 2 | 1/2 (Δ[KNO3])/(Δt) SNi | 1 | 1 | (Δ[S1Ni1])/(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[K2S])/(Δt) = -(Δ[Ni(NO3)2])/(Δt) = 1/2 (Δ[KNO3])/(Δt) = (Δ[S1Ni1])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| K2S | nickel(II) nitrate | potassium nitrate | nickel(II) sulfide formula | K2S | Ni(NO_3)_2 | KNO_3 | SNi Hill formula | K2S | N_2NiO_6 | KNO_3 | NiS name | | nickel(II) nitrate | potassium nitrate | nickel(II) sulfide IUPAC name | | nickel(+2) dinitrate | potassium nitrate | sulfanylidenenickel

| K2S | nickel(II) nitrate | potassium nitrate | nickel(II) sulfide molar mass | 110.26 g/mol | 182.7 g/mol | 101.1 g/mol | 90.75 g/mol phase | | solid (at STP) | solid (at STP) | melting point | | 57 °C | 334 °C | boiling point | | 137 °C | | density | | 1.77 g/cm^3 | | solubility in water | | | soluble | odor | | | odorless |