MgSiO3 = MgO + SiO2

MgSiO_3 magnesium metasilicate ⟶ MgO magnesium oxide + SiO_2 silicon dioxide

Balance the chemical equation algebraically: MgSiO_3 ⟶ MgO + SiO_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 MgSiO_3 ⟶ c_2 MgO + c_3 SiO_2 Set the number of atoms in the reactants equal to the number of atoms in the products for Mg, O and Si: Mg: | c_1 = c_2 O: | 3 c_1 = c_2 + 2 c_3 Si: | c_1 = 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 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | MgSiO_3 ⟶ MgO + SiO_2

⟶ +

magnesium metasilicate ⟶ magnesium oxide + silicon dioxide

Construct the equilibrium constant, K, expression for: MgSiO_3 ⟶ MgO + SiO_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: MgSiO_3 ⟶ MgO + SiO_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 MgSiO_3 | 1 | -1 MgO | 1 | 1 SiO_2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression MgSiO_3 | 1 | -1 | ([MgSiO3])^(-1) MgO | 1 | 1 | [MgO] SiO_2 | 1 | 1 | [SiO2] 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 = ([MgSiO3])^(-1) [MgO] [SiO2] = ([MgO] [SiO2])/([MgSiO3])

Construct the rate of reaction expression for: MgSiO_3 ⟶ MgO + SiO_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: MgSiO_3 ⟶ MgO + SiO_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 MgSiO_3 | 1 | -1 MgO | 1 | 1 SiO_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 MgSiO_3 | 1 | -1 | -(Δ[MgSiO3])/(Δt) MgO | 1 | 1 | (Δ[MgO])/(Δt) SiO_2 | 1 | 1 | (Δ[SiO2])/(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[MgSiO3])/(Δt) = (Δ[MgO])/(Δt) = (Δ[SiO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| magnesium metasilicate | magnesium oxide | silicon dioxide formula | MgSiO_3 | MgO | SiO_2 Hill formula | MgSiO_3 | MgO | O_2Si name | magnesium metasilicate | magnesium oxide | silicon dioxide IUPAC name | magnesium dioxido(oxo)silane | oxomagnesium | dioxosilane

| magnesium metasilicate | magnesium oxide | silicon dioxide molar mass | 100.39 g/mol | 40.304 g/mol | 60.083 g/mol phase | | solid (at STP) | solid (at STP) melting point | | 2852 °C | 1713 °C boiling point | | 3600 °C | 2950 °C density | | 3.58 g/cm^3 | 2.196 g/cm^3 solubility in water | | | insoluble odor | | odorless | odorless