21. Solving a chemistry problem

2. The process is represented by the following equation: 2NO↔N2 O2; ΔН > 0. Write the expressions: - for the rate of direct reaction; - for the speed of the reverse reaction; - for the chemical equilibrium constant. Where does the equilibrium shift when a) the pressure in the system decreases; b) with increasing temperature; c) with increasing O2 concentration?