Periodic Trends Acid

Rank the following compounds in order of decreasing acid strength using periodic trends.
Rank the acids from strongest to weakest. If any compounds are equal in strength, please indicate.
H2Se, HI, HBr, MgH2

Without consulting the table of acid-dissociation constants, match the following acids to the given Ka1 values.
H2S, H2SO3, H2SO4

Ka1 values: 1.7 x 10^-7, 1.7 x 10^-2, very large

Classify each salt as acidic, basic, or neutral.
CH3NH3NO3, NaF, BaBr2

Additional Requirements

Level of Detail: Show all work
Other Requirements: Please explain how you classified each and why. What is the chemical background? Please let me know if the question is unclear. I can clarify.