Input interpretation
H_2SO_4 sulfuric acid + Cd cadmium ⟶ H_2O water + S mixed sulfur + CdSO_4 cadmium sulfate
Balanced equation
Balance the chemical equation algebraically: H_2SO_4 + Cd ⟶ H_2O + S + CdSO_4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2SO_4 + c_2 Cd ⟶ c_3 H_2O + c_4 S + c_5 CdSO_4 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, S and Cd: H: | 2 c_1 = 2 c_3 O: | 4 c_1 = c_3 + 4 c_5 S: | c_1 = c_4 + c_5 Cd: | c_2 = c_5 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_4 = 1 and solve the system of equations for the remaining coefficients: c_1 = 4 c_2 = 3 c_3 = 4 c_4 = 1 c_5 = 3 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 4 H_2SO_4 + 3 Cd ⟶ 4 H_2O + S + 3 CdSO_4
Structures
+ ⟶ + +
Names
sulfuric acid + cadmium ⟶ water + mixed sulfur + cadmium sulfate
Equilibrium constant
Construct the equilibrium constant, K, expression for: H_2SO_4 + Cd ⟶ H_2O + S + CdSO_4 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: 4 H_2SO_4 + 3 Cd ⟶ 4 H_2O + S + 3 CdSO_4 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 H_2SO_4 | 4 | -4 Cd | 3 | -3 H_2O | 4 | 4 S | 1 | 1 CdSO_4 | 3 | 3 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2SO_4 | 4 | -4 | ([H2SO4])^(-4) Cd | 3 | -3 | ([Cd])^(-3) H_2O | 4 | 4 | ([H2O])^4 S | 1 | 1 | [S] CdSO_4 | 3 | 3 | ([CdSO4])^3 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 = ([H2SO4])^(-4) ([Cd])^(-3) ([H2O])^4 [S] ([CdSO4])^3 = (([H2O])^4 [S] ([CdSO4])^3)/(([H2SO4])^4 ([Cd])^3)
Rate of reaction
Construct the rate of reaction expression for: H_2SO_4 + Cd ⟶ H_2O + S + CdSO_4 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: 4 H_2SO_4 + 3 Cd ⟶ 4 H_2O + S + 3 CdSO_4 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 H_2SO_4 | 4 | -4 Cd | 3 | -3 H_2O | 4 | 4 S | 1 | 1 CdSO_4 | 3 | 3 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 H_2SO_4 | 4 | -4 | -1/4 (Δ[H2SO4])/(Δt) Cd | 3 | -3 | -1/3 (Δ[Cd])/(Δt) H_2O | 4 | 4 | 1/4 (Δ[H2O])/(Δt) S | 1 | 1 | (Δ[S])/(Δt) CdSO_4 | 3 | 3 | 1/3 (Δ[CdSO4])/(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 = -1/4 (Δ[H2SO4])/(Δt) = -1/3 (Δ[Cd])/(Δt) = 1/4 (Δ[H2O])/(Δt) = (Δ[S])/(Δt) = 1/3 (Δ[CdSO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| sulfuric acid | cadmium | water | mixed sulfur | cadmium sulfate formula | H_2SO_4 | Cd | H_2O | S | CdSO_4 Hill formula | H_2O_4S | Cd | H_2O | S | CdO_4S name | sulfuric acid | cadmium | water | mixed sulfur | cadmium sulfate IUPAC name | sulfuric acid | cadmium | water | sulfur |
Substance properties
| sulfuric acid | cadmium | water | mixed sulfur | cadmium sulfate molar mass | 98.07 g/mol | 112.414 g/mol | 18.015 g/mol | 32.06 g/mol | 208.47 g/mol phase | liquid (at STP) | solid (at STP) | liquid (at STP) | solid (at STP) | melting point | 10.371 °C | 320.9 °C | 0 °C | 112.8 °C | boiling point | 279.6 °C | 765 °C | 99.9839 °C | 444.7 °C | density | 1.8305 g/cm^3 | 8.65 g/cm^3 | 1 g/cm^3 | 2.07 g/cm^3 | solubility in water | very soluble | insoluble | | | surface tension | 0.0735 N/m | | 0.0728 N/m | | dynamic viscosity | 0.021 Pa s (at 25 °C) | | 8.9×10^-4 Pa s (at 25 °C) | | odor | odorless | odorless | odorless | |
Units