What is the Ka of a .168 M solution of hydrocyanic acid (HCN) with a pH of 3.15?

Ans. : frostbite is when exposure to cold temperatures causes freezing to the skin or other tissues. it most commonly affects the hands, feet, and face. the longer areas are exposed to cold, typically the worse the frostbite. the water temperature used for rewarming a frostbitten part should be : (102 -105) f degrees.

Idon’t know what the answer is i wish i could