H2SO4 + O2 + Cr = H2O + Cr2(SO4)3

H_2SO_4 sulfuric acid + O_2 oxygen + Cr chromium ⟶ H_2O water + Cr_2(SO_4)_3 chromium sulfate

Balance the chemical equation algebraically: H_2SO_4 + O_2 + Cr ⟶ H_2O + Cr_2(SO_4)_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2SO_4 + c_2 O_2 + c_3 Cr ⟶ c_4 H_2O + c_5 Cr_2(SO_4)_3 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, S and Cr: H: | 2 c_1 = 2 c_4 O: | 4 c_1 + 2 c_2 = c_4 + 12 c_5 S: | c_1 = 3 c_5 Cr: | c_3 = 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_5 = 1 and solve the system of equations for the remaining coefficients: c_1 = 3 c_2 = 3/2 c_3 = 2 c_4 = 3 c_5 = 1 Multiply by the least common denominator, 2, to eliminate fractional coefficients: c_1 = 6 c_2 = 3 c_3 = 4 c_4 = 6 c_5 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 6 H_2SO_4 + 3 O_2 + 4 Cr ⟶ 6 H_2O + 2 Cr_2(SO_4)_3

+ + ⟶ +

sulfuric acid + oxygen + chromium ⟶ water + chromium sulfate

K_c = ([H2O]^6 [Cr2(SO4)3]^2)/([H2SO4]^6 [O2]^3 [Cr]^4)

rate = -1/6 (Δ[H2SO4])/(Δt) = -1/3 (Δ[O2])/(Δt) = -1/4 (Δ[Cr])/(Δt) = 1/6 (Δ[H2O])/(Δt) = 1/2 (Δ[Cr2(SO4)3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sulfuric acid | oxygen | chromium | water | chromium sulfate formula | H_2SO_4 | O_2 | Cr | H_2O | Cr_2(SO_4)_3 Hill formula | H_2O_4S | O_2 | Cr | H_2O | Cr_2O_12S_3 name | sulfuric acid | oxygen | chromium | water | chromium sulfate IUPAC name | sulfuric acid | molecular oxygen | chromium | water | chromium(+3) cation trisulfate

| sulfuric acid | oxygen | chromium | water | chromium sulfate molar mass | 98.07 g/mol | 31.998 g/mol | 51.9961 g/mol | 18.015 g/mol | 392.2 g/mol phase | liquid (at STP) | gas (at STP) | solid (at STP) | liquid (at STP) | liquid (at STP) melting point | 10.371 °C | -218 °C | 1857 °C | 0 °C | boiling point | 279.6 °C | -183 °C | 2672 °C | 99.9839 °C | 330 °C density | 1.8305 g/cm^3 | 0.001429 g/cm^3 (at 0 °C) | 7.14 g/cm^3 | 1 g/cm^3 | 1.84 g/cm^3 solubility in water | very soluble | | insoluble | | surface tension | 0.0735 N/m | 0.01347 N/m | | 0.0728 N/m | dynamic viscosity | 0.021 Pa s (at 25 °C) | 2.055×10^-5 Pa s (at 25 °C) | | 8.9×10^-4 Pa s (at 25 °C) | odor | odorless | odorless | odorless | odorless | odorless