Ca + SnCl2 = CaCl2 + Sn

Ca calcium + SnCl_2 stannous chloride ⟶ CaCl_2 calcium chloride + Sn white tin

Balance the chemical equation algebraically: Ca + SnCl_2 ⟶ CaCl_2 + Sn Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Ca + c_2 SnCl_2 ⟶ c_3 CaCl_2 + c_4 Sn Set the number of atoms in the reactants equal to the number of atoms in the products for Ca, Cl and Sn: Ca: | c_1 = c_3 Cl: | 2 c_2 = 2 c_3 Sn: | c_2 = 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 = 1 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Ca + SnCl_2 ⟶ CaCl_2 + Sn

+ ⟶ +

calcium + stannous chloride ⟶ calcium chloride + white tin

Construct the equilibrium constant, K, expression for: Ca + SnCl_2 ⟶ CaCl_2 + Sn 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: Ca + SnCl_2 ⟶ CaCl_2 + Sn 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 Ca | 1 | -1 SnCl_2 | 1 | -1 CaCl_2 | 1 | 1 Sn | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Ca | 1 | -1 | ([Ca])^(-1) SnCl_2 | 1 | -1 | ([SnCl2])^(-1) CaCl_2 | 1 | 1 | [CaCl2] Sn | 1 | 1 | [Sn] 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 = ([Ca])^(-1) ([SnCl2])^(-1) [CaCl2] [Sn] = ([CaCl2] [Sn])/([Ca] [SnCl2])

Construct the rate of reaction expression for: Ca + SnCl_2 ⟶ CaCl_2 + Sn 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: Ca + SnCl_2 ⟶ CaCl_2 + Sn 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 Ca | 1 | -1 SnCl_2 | 1 | -1 CaCl_2 | 1 | 1 Sn | 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 Ca | 1 | -1 | -(Δ[Ca])/(Δt) SnCl_2 | 1 | -1 | -(Δ[SnCl2])/(Δt) CaCl_2 | 1 | 1 | (Δ[CaCl2])/(Δt) Sn | 1 | 1 | (Δ[Sn])/(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[Ca])/(Δt) = -(Δ[SnCl2])/(Δt) = (Δ[CaCl2])/(Δt) = (Δ[Sn])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| calcium | stannous chloride | calcium chloride | white tin formula | Ca | SnCl_2 | CaCl_2 | Sn Hill formula | Ca | Cl_2Sn | CaCl_2 | Sn name | calcium | stannous chloride | calcium chloride | white tin IUPAC name | calcium | dichlorotin | calcium dichloride | tin

| calcium | stannous chloride | calcium chloride | white tin molar mass | 40.078 g/mol | 189.6 g/mol | 111 g/mol | 118.71 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | solid (at STP) melting point | 850 °C | 246 °C | 772 °C | 231.9 °C boiling point | 1484 °C | 652 °C | | 2602 °C density | 1.54 g/cm^3 | 3.354 g/cm^3 | 2.15 g/cm^3 | 7.31 g/cm^3 solubility in water | decomposes | | soluble | insoluble dynamic viscosity | | 7 Pa s (at 25 °C) | | 0.001 Pa s (at 600 °C) odor | | odorless | | odorless