Hey everyone, so for this example question, it says for the reaction we have 4 moles of hydrogen bromide gas reacting with one mole of oxygen gas to produce 2 moles of bromine gas +2 water liquids. We're told that the equilibrium constant is 0.063 at 400 Kelvin. Now if the reaction quotient is 0.100, which of the following statements is true?
All right, so remember our equilibrium constant is K and our reaction quotient is Q. When we have both Q&K, we can compare them to one another to tell which direction our chemical reaction will shift. So do a number line. Here K represents our equilibrium amount, so put it in the middle. Now, is Q bigger than, less than or equal to K? Well, Q is 0.100, so Q is larger. But remember, Q will always shift towards K. To maintain equilibrium. The direction queue shifts in the same direction that our chemical reaction will shift, So our chemical reaction also shifts in the reverse direction.
Now remember, the direction we're moving towards will be increasing an amount. Since we're moving towards the reactants, our reactants would be increasing in amount and things must be balanced. If our reactant site is increasing, then our product site has to be decreasing. Based on this information, we have to say which of the following statements is true.
So if we take a look here, it says HBR will decrease. Well HBR is a reactant. We're moving towards a reactant site so it should be increasing not decreasing. So this is false, O2 will increase. This is true. It's a reactant, so it should be going up. Next BR2 will increase, H2O will increase. Both of these are products we're moving away from the product side, so they should be decreasing an amount, not increasing amount. So out of all the statements, only option B is true.