What happens to a production possibilities curve whenever there is too much labor? If too much labor is added to a country's production, what happens to the production possibilities curve?
What should happen? It grows. A production possibilty curve shows that the number of goods that can be produced is limited. If there is "more workforce than needed" (supply of work exceeds demand), prices for work descend, due to competition. That means that you can employ more people with the same capital. So if there are enough of the other limiting production factors (such as soil) available, you can produce more of both products.
Of course the product which is more labour-intensive (in the often used example of butter and guns that would probably be the guns) will profit much more from that.