Consider the acid strength of the carboxylic acids: (i) PhCOOH (ii) o - NO2C6H4COOH (iii) p-NO2C6H4COOH (iv) m-NO2C6H4COOH

Question

Consider the acid strength of the carboxylic acids: (i) PhCOOH (ii) o - NO2C6H4COOH (iii) p-NO2C6H4COOH (iv) m-NO2C6H4COOH (A) i > ii > iii > iv (B) iv > iii > ii > i (C) ii > iii > iv > i (D) ii > iv > iii > i

Tardigrade Admin · Accepted Answer

Due to -I and -R effects of -N02 group, nitrobenzoic acids are stronger acids than benzoic acid. Due to ortho-effect, o-nitrobenzoic acid is the strongest acid.
In p-nitrobenzoic acid, both - R effect and -I effect of the

- N O_{2}

group increase the acidity while in m-nitrobenzoic acid only the weaker - I effect increases the acidity. Hence, o-nitrobenzoic acid > p-nitrobenzoic acid > m-nitrobenzoic acid > benzoic acid.

Q. Consider the acid strength of the carboxylic acids:
(i) $P h COO H$
(ii) $o - N O_{2} C_{6} H_{4} COO H$
(iii) $p - N O_{2} C_{6} H_{4} COO H$
(iv) $m - N O_{2} C_{6} H_{4} COO H$

$i > ii > iii > i v$

$i v > iii > ii > i$

$ii > iii > i v > i$

$ii > i v > iii > i$

Q. Consider the acid strength of the carboxylic acids: (i) PhCOOH (ii) o−NO2​C6​H4​COOH (iii) p−NO2​C6​H4​COOH (iv) m−NO2​C6​H4​COOH

i>ii>iii>iv

iv>iii>ii>i

ii>iii>iv>i

ii>iv>iii>i

Q. Consider the acid strength of the carboxylic acids:
(i) $P h COO H$
(ii) $o - N O_{2} C_{6} H_{4} COO H$
(iii) $p - N O_{2} C_{6} H_{4} COO H$
(iv) $m - N O_{2} C_{6} H_{4} COO H$

$i > ii > iii > i v$

$i v > iii > ii > i$

$ii > iii > i v > i$

$ii > i v > iii > i$