In which of the following equilibrium systems will an increase in the pressure have no effect on the concentrations of products and reactants?
a. H2(g) + F2(g) 2 HF(g)
b. N2(g) + 3 H2(g) 2 NH3(g)
c. CaCO3(s) CaO(s) + CO2(g)
d. 2 NOBr(g) 2 NO(g) + Br2(g)
Answer: a