Question

Calculate the percent ionization of a 4.00 m formic acid (HCHO_2​) solution in water. (K_a​ for formic acid is 1.8×10^(−4)).

a) 0.45%
b) 0.22%
c) 2.22%

Answer 1

The percent ionization of the 4.00 M formic acid solution in water is 0.45%.

Step-by-step explanation:

To calculate the percent ionization of a 4.00 M formic acid solution in water, we can use the equilibrium constant expression.

The equilibrium constant, Ka, for formic acid (HCHO2) is given as 1.8×10−4.

We substitute the concentrations into the equilibrium constant expression, make the usual simplifying assumptions, and solve for the final concentration of the formic acid.

The percent ionization of formic acid is determined to be 0.45%.