Does this flight go across the Atlantic?
No, I think not. Last I heard Ghana is in west Africa.
Unless Ghana moved to near Florida or Rio de Janerio I think it is safe to say it is NOT a transatlantic flight.
If your taking QA then you get 20 kilos check-in luggage. Very cheap of a "5 star airline".
Join Privilege Club of Qatar Airways and you get more allowance. GOOD LUCK!