K_{a} = ( [H^{+}] [A¯] ) / [HA] ( our dissociation equation set up )

So, H^+ = 10^-pH

10^ - 3.75

= 1.778 X 10^-4

------A^- is one to one with H^+ and we are given HA.

Ka = (1.778 X 10^-4)(1.778 X 10^-4)/1.0 M

**= 3.2 X 10^-8**

**======**

K_{a} = ( [H^{+}] [A¯] ) / [HA] ( our dissociation equation set up )

So, H^+ = 10^-pH

10^ - 3.75

= 1.778 X 10^-4

------A^- is one to one with H^+ and we are given HA.

Ka = (1.778 X 10^-4)(1.778 X 10^-4)/1.0 M

**= 3.2 X 10^-8**

**======**

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