Question

Calculate the reaction quotient, Qc, for the following reaction:2NO2(g) + 7H2(g) → 2NH3(g) + 4H2O(g)at a temperature of 300 K and a pressure of 0.5 atm for each gas species. The equilibrium constants, Kc, at the same temperature and pressure are:Kc = 0.0080 for the reverse reactionKc = 7.2 × 10^-7 for the forward reaction

Answer 1

To calculate the reaction quotient, Qc, we need to use the concentrations of the reactants and products in the reaction. Since the pressure of each gas species is given, we can use the ideal gas law to find the concentrations:PV = nRTWhere P is pressure, V is volume, n is the number of moles, R is the ideal gas constant  0.0821 L atm/mol K , and T is temperature. We can rearrange the equation to find the concentration  n/V :n/V = P/RTSince the pressure and temperature are the same for all species, we can use the given pressure  0.5 atm  and temperature  300 K  to find the concentration of each species:Concentration =  0.5 atm  /  0.0821 L atm/mol K  300 K  = 0.0203 mol/LNow we can calculate the reaction quotient, Qc, using the concentrations:Qc = [NH3]^2  [H2O]^4 /  [NO2]^2  [H2]^7 Since the concentrations of all species are the same  0.0203 mol/L , we can plug in the values:Qc =  0.0203 ^2   0.0203 ^4 /   0.0203 ^2   0.0203 ^7 Qc =  0.0203 ^6 /  0.0203 ^9Qc = 1 /  0.0203 ^3Qc  12194.7So, the reaction quotient, Qc, for the given reaction at 300 K and 0.5 atm for each gas species is approximately 12194.7.