When to exchange queens

Exchange queens when u want to play without queens :)

Thanks, Tony. That was very helpful.

I would exchange queens if my king is poorly protected to avoid the constant threat of being checked.  Also as someone said before, if you are up material try to take away every opportuntiy for your opponent to get any counterplay.
If you are playing a much stronger opponent it could help you simplify the board although someone told me that this isn't really recommended as you wont learn as much.
As for the 3d side debate, I can't make out the pieces too well either, don't think you needed to so rude in your reply but I do enjoy a bit of internet arguing. 

Thanks 'gibbo. See, I can take what you said about the pieces. No problem. You gave me some good feedback and then you commented on the icons I used. Yes, I got a bit rude, you're right. I bristle a bit when people are referring to the way I posted the board as "awful" and "annoying" and then not even answering the thread question. I just think that is rude. But, I should have been nicer.

One time it is desirable to exchange queens is whenever circumstances have prevented you from being able to castle.  Just a rule of thumb, undoubtedly exceptions.

Well, first off, why did you play Qe7? All that does is block the reasonable development of the bishop. There are easier ways to defend e5, such as d6. You can fianchetto the bishop, but then d5 would be required, made impossible by dxc6. As for your question on the queen trade, it is often easier to win by trading, but also because his queen wasn't serving a real purpose, while yours could potentially be active by Qa3. Perhaps he wasn't thinking of those things and just wanted to trade pieces... 

Another good time to exchange Q's would be whenever playing Capt Jack.

Exchanging Queens in a roughly equal position means you will typically play an endgame, and the winner will be decided by pawn promotion.

Leaving Queens on the board leaves you with the danger that someone will get checkmated.

Whenever you are ahead a pawn or two, exchanging Queens is probably the easiest way to win, assuming you possess reasonable endgame knowledge.

Even if you are up a couple pawn, or even a whole minor piece, with Queens still on the board, you can get checkmated in the middlegame.

So if you have decent endgame knowledge, and a material advantage, exchanging Queens is a no brainer.

And if you want to cut down on the complications and calculations endemic to the game, exchange both Queens and Knights.  This makes the game dramatically more simple, and much less of a mind-bender.  

In all these situations, the stronger endgame player will typically win out.

Ultimately, it's a matter of taste, do you like complications and middlegame mating attacks, or do you prefer to slowly strangle your opponent in the endgame.

Take your pick.

For some reason, you still appear not to be grasping the fact that, for some people at least, the reason they were "not even answering the thread question" is precisely because of the practically illegible way in which you presented it. Some people seem to have less trouble with those pieces than others, but for me at least, I'd pretty much have to transfer your moves onto a separate board to even figure out what was going on, let alone answer your question. So for anyone who struggles with distinguishing one of your pieces from another and is not willing to put that amount of time into correcting for a deliberate decision you made to override the default settings and present your board in a very confusing way, complaining to you about the "awful" and "annoying" board you posted is just about the only response they're able to give you.

You seem to be grasping my point. I totally get exchanging queens and I have done so many, many times. In no way do I think it is unethical...at all (as someone suggested). And yes, my Qe7 was at best a mistake if not a blunder. I have simply experienced times when my opponent has opted to exchange queens for, what appears to me, to be no advantage. Maybe some people just like to lose the queens to simplify the game, as you suggested. Personally, I like complex endgames. When I have sacrificed or exchanged queens it has almost always been during the endgame. However, I have definitely gained some good insights from this thread; from those who have added something helpful.

Qe7 was a total brain fart.

I created a thread for Queen Exchange already!

http://www.chess.com/forum/view/general/queen-exchange2

And if you want a DEFINITIVE answer for exchanging pieces in general, buy the following two books by the former World Correspondence Champion, Gennady Nesis--

• Tactical Chess Exchanges, (1992)
• Exchanging to Win in the Endgame, (1991)

Or... The street-guide says:

'' If your opponent is higher-rated/better than you are they WANT you to exchange Q's! In fact they want you to exchange all the minor-pieces secure in the knowledge they are probably able to play a superior-endgame & defeat you !!

Think carefully before doing so... '' 

There is a great book that has a chapter on this subject 
from the middlegame to the endgame by Mednis

http://www.amazon.com/From-Middlegame-Endgame-Edmar-Mednis/dp/1857440609

I'll just add one thing. Sometimes it's good to exchange queens before a middle game attack especially if the opponent is over-extended and has a lot of weak points to defend.

Fair comment, maybe I would have acted similiar, good luck with your chess

And I still think those icons are horrible, hard to decipher, and in general poor taste.