H2 + Cu = HCu2

H_2 (hydrogen) + Cu (copper) ⟶ HCu2

Balance the chemical equation algebraically: H_2 + Cu ⟶ HCu2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2 + c_2 Cu ⟶ c_3 HCu2 Set the number of atoms in the reactants equal to the number of atoms in the products for H and Cu: H: | 2 c_1 = c_3 Cu: | c_2 = 2 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 = 4 c_3 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | H_2 + 4 Cu ⟶ 2 HCu2

+ ⟶ HCu2

hydrogen + copper ⟶ HCu2

K_c = [HCu2]^2/([H2] [Cu]^4)

rate = -(Δ[H2])/(Δt) = -1/4 (Δ[Cu])/(Δt) = 1/2 (Δ[HCu2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| hydrogen | copper | HCu2 formula | H_2 | Cu | HCu2 name | hydrogen | copper | IUPAC name | molecular hydrogen | copper |

| hydrogen | copper | HCu2 molar mass | 2.016 g/mol | 63.546 g/mol | 128.1 g/mol phase | gas (at STP) | solid (at STP) | melting point | -259.2 °C | 1083 °C | boiling point | -252.8 °C | 2567 °C | density | 8.99×10^-5 g/cm^3 (at 0 °C) | 8.96 g/cm^3 | solubility in water | | insoluble | dynamic viscosity | 8.9×10^-6 Pa s (at 25 °C) | | odor | odorless | odorless |