which solution at 25o C is strongest?
A. Chlorous acid, Ka=1.10x10^-2
B. salicylic acid, Ka=1.10x10^-3
C. chloroacetic acid, Ka= 1.41x10^-3
D. propanoic acid, Ka= 1.41x10^-5

Question

which solution at 25o C is strongest?
A. Chlorous acid, Ka=1.10x10^-2
B. salicylic acid, Ka=1.10x10^-3
C. chloroacetic acid, Ka= 1.41x10^-3
D. propanoic acid, Ka= 1.41x10^-5

matt101 · Answer

Ka is the acid dissociation constant - the larger the constant, the more acidic the acid. You find its value from the equilibirum concentrations: [A-][H+]/[HA]. You can see that if your solution is very acidic, [H+] will be very high, causing Ka to be high too.

Of your choices, A has the highest Ka, so it is most acidic.