Input interpretation
magnesium + chromium(III) oxide ⟶ magnesium oxide + chromium
Balanced equation
Balance the chemical equation algebraically: + ⟶ + Add stoichiometric coefficients, c_i, to the reactants and products: c_1 + c_2 ⟶ c_3 + c_4 Set the number of atoms in the reactants equal to the number of atoms in the products for Mg, Cr and O: Mg: | c_1 = c_3 Cr: | 2 c_2 = c_4 O: | 3 c_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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 3 c_2 = 1 c_3 = 3 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 + ⟶ 3 + 2
Structures
+ ⟶ +
Names
magnesium + chromium(III) oxide ⟶ magnesium oxide + chromium
Reaction thermodynamics
Enthalpy
| magnesium | chromium(III) oxide | magnesium oxide | chromium molecular enthalpy | 0 kJ/mol | -1140 kJ/mol | -601.6 kJ/mol | 0 kJ/mol total enthalpy | 0 kJ/mol | -1140 kJ/mol | -1805 kJ/mol | 0 kJ/mol | H_initial = -1140 kJ/mol | | H_final = -1805 kJ/mol | ΔH_rxn^0 | -1805 kJ/mol - -1140 kJ/mol = -665.1 kJ/mol (exothermic) | | |
Entropy
| magnesium | chromium(III) oxide | magnesium oxide | chromium molecular entropy | 33 J/(mol K) | 81 J/(mol K) | 27 J/(mol K) | 24 J/(mol K) total entropy | 99 J/(mol K) | 81 J/(mol K) | 81 J/(mol K) | 48 J/(mol K) | S_initial = 180 J/(mol K) | | S_final = 129 J/(mol K) | ΔS_rxn^0 | 129 J/(mol K) - 180 J/(mol K) = -51 J/(mol K) (exoentropic) | | |
Chemical names and formulas
| magnesium | chromium(III) oxide | magnesium oxide | chromium Hill formula | Mg | Cr_2O_3 | MgO | Cr name | magnesium | chromium(III) oxide | magnesium oxide | chromium IUPAC name | magnesium | | oxomagnesium | chromium
Substance properties
| magnesium | chromium(III) oxide | magnesium oxide | chromium molar mass | 24.305 g/mol | 151.99 g/mol | 40.304 g/mol | 51.9961 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | solid (at STP) melting point | 648 °C | 2435 °C | 2852 °C | 1857 °C boiling point | 1090 °C | 4000 °C | 3600 °C | 2672 °C density | 1.738 g/cm^3 | 4.8 g/cm^3 | 3.58 g/cm^3 | 7.14 g/cm^3 solubility in water | reacts | insoluble | | insoluble odor | | | odorless | odorless
Units
