Azerbaijan is 12% larger than Serbia.
Area: 86,600 km2 World Factbook
Population: 9,686,210 (July 2014) World Factbook
Azerbaijan, officially the Republic of Azerbaijan, is the largest country in the Caucasus region located at the crossroads of Western Asia and Eastern Europe. It is bounded by the Caspian Sea to the east, Russia to the north, Georgia to the northwest, Armenia to the west and Iran to the south. Wikipedia
Area: 77,474 km2 World Factbook
Population: 7,209,764 (July 2014) World Factbook
Serbia, officially the Republic of Serbia, is a country located at the crossroads of Central and Southeast Europe, covering the southern part of the Pannonian Plain and the central Balkans. Wikipedia