HF (g) = hydrogen fluoride       ->    HF (aq) = hydrofluoric acid HBr (g) = hydrogen bromide    ->     HBr (aq) = hydrobromic acid HCl (g) = hydrogen chloride     ->    HCl (aq) = hydrochloric acid H2S (g) = hydrogen sulfide      ->    H2S (aq) = hydrosulfuricacid