am not sure of the value that you need to solve this problem. this is how it appear in huang textbook problem 7.9

Huang: Problem 7.9: A dilute mixture of H, and O2 gases is kept at constant temperature T. Initially: NH, = no, no, = no/2, and there was no H2O present. After a certain time an equilibrium situation with densities of the three components H2, 02, and H2O is established. Find the equilibrium densities of the three components: NH, = ni, no, = n2, and nho = n3 as a function of T and no