iTutor Chemistry Updates

Hi guys I'm just uploading this for the moment - I suspect I'm going to have to come back to it. I'm going off to stare at notes for a few hours and see if I can find how to work this out. We just started these types of equations so I'm a bit of a n00b - and the lecturer has sneakily rearranged the type of values we need to determine. Leaving me all sorts of confused. 1st question has she reversed the forwards and backwards sign here? The 2Hl(g) is the forward product - right?