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 required 1.4 KJ/mol heat for it's comptate ionzatation and enthalpy of netralization of the strong monobasic acid with a strong monoacidic base is -57.3 KJ/mol . What is the % ionzation of the weak acid in molar solution ?

Options

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

Answer

B

Explanation

`HA rarr H^(+) + A^(-), Delta_(r)H = 1.4 kJ//mol`
`Delta H_("neutralization") = Delta H_("ionization") + Delta_(r)H`
`(H^(+) + OH^(-) rarr H_(2)O)`
`-55.95 = Delta H_("ionization")-57.3`
`Delta H_("ionization")` for 1M HA = 1.35 kJ/mol % heat utilizsed by 1M acid for ionization
`= (1.35)/(1.4) xx 100 = 96.43%`
so, acid is `100-96.3 = 3.57%` ionizsed