0.279 M 아니스 산 용액의 pH

0.279 M 아니스 산 용액의 pH

0.279 M anisic acid 용액의 pH

Ka = 3.38×10^(-5)

 

 

Anisic acid (Ka = 3.38×10^(-5)) is found in anise seeds

and is used as a flavoring agent.

For a 0.279 M solution of anisic acid, calculate

a) [H^+]

b) [OH^-]

c) pH

d) % ionization

 

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HA(aq) ⇌ H^+(aq) + A^-(aq)

Ka = [H^+][A^-] / [HA] = (x)(x) / (C–x)

( 참고 https://ywpop.tistory.com/4294 )

 

 

 

C–x ≒ C 라 근사처리하면,

Ka = x^2 / C

 

x = [Ka × C]^(1/2)

= [(3.38×10^(-5)) × 0.279]^(1/2)

= 0.00307 M = [H^+]

 

 

 

pH = –log[H^+]

= –log(0.00307) = 2.51

 

 

 

이온화 백분율(%) = ([H^+] / [HA]) × 100

( 참고 https://ywpop.tistory.com/3146 )

 

= (0.00307 / 0.279) × 100 = 1.10%