The enthalpy of neutralization of a weak monoprotic acid (HA) in 1 M solution with a strong base is -55.95 kJ/mol. If the unionized acid is required 1.4 kJ/mol heat for it's complete ionization and enthalpy of neutralization of the strong monobasic acid with a strong monoacidic base is -57.3 kJ/mol. What is the % ionization of the weak acid in molar solution?

Options

A. `1 %`
B. `3.57 %`
C. `35.7%`
D. `10%`

Answer

B

Explanation

`HA to H ^(+) + A ^(-) Delta _(r) H= 1. 4 kJ // mol , Delta H _("ncatralization") + Delta_(r) H`
` (H ^(+) + OH ^(-) to H _(2) O ) - 55 95 = Delta H _("ionization ")` for ` 1 MHA = 1. 35 J // mol`
`%` heat utilized by 1 M acid for ionization `= (1.35)/(1.4) xx 100 = 96. 43 %` so acid is `100 - 96.43 = 3.57%` ionized