Question

Which one of the following orders of acidic strength is correct ?

• A. RCOOH > HOH > HC $\equiv$ CH > ROH
• B. RCOOH > HC $\equiv$ CH > HOH >ROH
• C. RCOOH >ROH > HOH > HC $\equiv$ CH
• D. RCOOH > HOH > ROH >HC $\equiv$ CH

Answer 1

Answer: (D)

RCOOH > HOH > ROH >HC $\equiv$ CH

Answer 2

Carboxylic acid is stronger than alcohol and water because after removal of proton, carboxylate ion is stabilised by resonance. Hence, correct order of acid strength is
$RCOOH > HOH > ROH > HC \equiv CH$
Which is based upon the rate of donation of proton or strength of base, thus order of basic strength is
$\bar{C} \equiv CH > R- \bar{O} > OH^- > RCOO^-$