Misc: What name is given to the study of lakes?

Questions

In 1748 Treaty of---------- , ends War of Austrian Succession. ?

In 1748 Treaty of Aix-la-Chapelle, ends War of ---------- Succession. ?

In 1867 US takes formal possession of ---------- from Russia ($7.2 million). ?

In 1867 US takes formal possession of Alaska from ---------- ($7.2 million). ?

In 1867 US takes formal possession of Alaska from Russia (---------- million). ?