Yield in sequence inside a loop?

Hello everyone, I'd like some help to understand the following code. I got the following cards inside the scene.

With the following code, I try to make the cards switch of positions.

 for (int i = 0; i < oNoSwitches; i++) {
             //Debug.Log ("Cambio de cartas numero: " + (i + 1));
             yield return switchCards();
         }

At first I thought the methods will be called one by one, waiting for the card switching to finish, but It doesn't go that way, instead the cards start to move randomly after some amount of time and doesnt wait for the cards to finish moving like I thought it would, How can I fix this? Thanks in advance