PCl5 = Cl2 + PCl3

phosphorus pentachloride ⟶ chlorine + phosphorus trichloride

Balance the chemical equation algebraically: ⟶ + Add stoichiometric coefficients, c_i, to the reactants and products: c_1 ⟶ c_2 + c_3 Set the number of atoms in the reactants equal to the number of atoms in the products for Cl and P: Cl: | 5 c_1 = 2 c_2 + 3 c_3 P: | 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: | | ⟶ +

⟶ +

phosphorus pentachloride ⟶ chlorine + phosphorus trichloride

| phosphorus pentachloride | chlorine | phosphorus trichloride Hill formula | Cl_5P | Cl_2 | Cl_3P name | phosphorus pentachloride | chlorine | phosphorus trichloride IUPAC name | pentachlorophosphorane | molecular chlorine | trichlorophosphane

| phosphorus pentachloride | chlorine | phosphorus trichloride molar mass | 208.2 g/mol | 70.9 g/mol | 137.3 g/mol phase | solid (at STP) | gas (at STP) | liquid (at STP) melting point | 148 °C | -101 °C | -112 °C boiling point | | -34 °C | 76 °C density | 3.6 g/cm^3 | 0.003214 g/cm^3 (at 0 °C) | 1.574 g/cm^3 solubility in water | reacts | | decomposes surface tension | | | 0.0291 N/m dynamic viscosity | | | 5.29×10^-4 Pa s (at 25 °C)