The elementary reaction 2 H 2 O ( g ) − ⇀ ↽ − 2 H 2 ( g ) + O 2 ( g ) proceeds at a certain temperature until the partial pressures of H 2 O , H 2 , and O 2 reach 0.0150 bar , 0.00550 bar , and 0.00500 bar respectively. What is the value of the equilibrium constant at this temperature?