For the reaction 2H2 + O2 -- 2H2O, how do I give an equation for the equilibrium constant in terms of the concentrations of products and reactants involved?

For any reaction, the equilibrium constant is given in the form: K = [products] / [reactants]

Where [ ] is used to denote the concentration of the species. 

Therefore we can substitute in for the molecules given above, which becomes, K = [H2O] / ([H2] x [O2]). 

But, we're not finished there. We have to remember the stoichiometric coefficients given in the balanced equation, and put them to the power of the respective molecules. 

This gives the final, correct answer, K = [H2O]2 / ([H2]2 x [O2]). 

LS
Answered by Liam S. Chemistry tutor

24653 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

What is the equilibrium constant?


How can I use an infrared spectrum with a mass spectrum to identify an unknown compound?


Describe the 3 types of isomers?


Give and explain 2 of the anomalous properties of ice caused by hydrogen bonding


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning