10.3.1 Expression for Kc

    Cards (11)

    • What is the first step in calculating KcK_{c}?

      Write the balanced equation
    • The stoichiometric coefficients in a balanced equation represent the molar ratios between reactants and products.
    • For the reaction N2(g)+N_{2}(g) +3H2(g)2NH3(g) 3H_{2}(g) \rightleftharpoons 2NH_{3}(g), the coefficient for H2H_{2} is 3
    • Reactants are the substances formed during a chemical reaction.
      False
    • ProductsProducts are the substances formed from the reaction.Products
    • What is the relationship between stoichiometric coefficients and the KcK_{c} expression?

      Exponents for concentrations
    • Stoichiometric coefficients are used as exponents in the KcK_{c} expression.
    • For the reaction 2NO(g)+2NO(g) +O2(g)2NO2(g) O_{2}(g) \rightleftharpoons 2NO_{2}(g), the KcK_{c} expression is Kc=K_{c} =[NO2]2[NO]2[O2] \frac{[NO_{2}]^{2}}{[NO]^{2}[O_{2}]} where [O2][O_{2}] has an exponent of 1
    • Identifying reactants and products is crucial for calculating KcK_{c}.
    • What does the equilibrium constant KcK_{c} express?

      Ratio of product to reactant concentrations
    • For the reaction N2+N_{2} +3H22NH3 3H_{2} \rightleftharpoons 2NH_{3}, the exponent for H2H_{2} in the KcK_{c} expression is 3