I am Chinese. Mr/Ms.Yozloy's answer is correct, and may I add something more here.
Here is what I know: some transcriptions of contries' names in Chinese came from Japanese (they share some same letters, which is called kanji, as you may know) in late 19th century. Here are some examples:
Japanese / Modern Chinese
America 米利坚 / 美利坚
England 英吉利 / 英格兰
Deutsch 独逸址 / 德意志
France 佛朗西 / 法兰西
The changes may come from the misunderstands in second translation(European language--Japanese--Chinese)or just because translators (they are all knowladged people at that time in China)want to show these contries' strength so that we can courage ourselves to run after them——at that time, China is a very weak country.
Actually there are changes after 1949:at first we named Mozambique “莫三鼻给”,however, Premier ZhouEnlai said that 鼻(nose) is not a good word here——and now we call Mozambique “莫桑比克”.