Input interpretation
H_2O_3Si (metasilicic acid) ⟶ H_2O (water) + SiO_2 (silicon dioxide)
Balanced equation
Balance the chemical equation algebraically: H_2O_3Si ⟶ H_2O + SiO_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O_3Si ⟶ c_2 H_2O + c_3 SiO_2 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O and Si: H: | 2 c_1 = 2 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: | | H_2O_3Si ⟶ H_2O + SiO_2
Structures
⟶ +
Names
metasilicic acid ⟶ water + silicon dioxide
Reaction thermodynamics
Enthalpy
| metasilicic acid | water | silicon dioxide molecular enthalpy | -1189 kJ/mol | -285.8 kJ/mol | -911 kJ/mol total enthalpy | -1189 kJ/mol | -285.8 kJ/mol | -911 kJ/mol | H_initial = -1189 kJ/mol | H_final = -1197 kJ/mol | ΔH_rxn^0 | -1197 kJ/mol - -1189 kJ/mol = -8.13 kJ/mol (exothermic) | |
Gibbs free energy
| metasilicic acid | water | silicon dioxide molecular free energy | -1092 kJ/mol | -237.1 kJ/mol | -856 kJ/mol total free energy | -1092 kJ/mol | -237.1 kJ/mol | -856 kJ/mol | G_initial = -1092 kJ/mol | G_final = -1093 kJ/mol | ΔG_rxn^0 | -1093 kJ/mol - -1092 kJ/mol = -0.7 kJ/mol (exergonic) | |
Equilibrium constant
![K_c = ([H2O] [SiO2])/[H2O3Si]](../image_source/f4e85b3c50876fa2bb363b320352567e.png)
K_c = ([H2O] [SiO2])/[H2O3Si]
Rate of reaction
![rate = -(Δ[H2O3Si])/(Δt) = (Δ[H2O])/(Δt) = (Δ[SiO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)](../image_source/1d800b1a5a8bff64dfa49b230e3273be.png)
rate = -(Δ[H2O3Si])/(Δt) = (Δ[H2O])/(Δt) = (Δ[SiO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| metasilicic acid | water | silicon dioxide formula | H_2O_3Si | H_2O | SiO_2 Hill formula | H_2O_3Si | H_2O | O_2Si name | metasilicic acid | water | silicon dioxide IUPAC name | dihydroxy-oxo-silane | water | dioxosilane
Substance properties
| metasilicic acid | water | silicon dioxide molar mass | 78.098 g/mol | 18.015 g/mol | 60.083 g/mol phase | solid (at STP) | liquid (at STP) | solid (at STP) melting point | 1704 °C | 0 °C | 1713 °C boiling point | | 99.9839 °C | 2950 °C density | 1 g/cm^3 | 1 g/cm^3 | 2.196 g/cm^3 solubility in water | | | insoluble surface tension | | 0.0728 N/m | dynamic viscosity | | 8.9×10^-4 Pa s (at 25 °C) | odor | | odorless | odorless
Units
