Question

The following reactions all have K < 1.

1) C6H5COO- (aq) + HClO (aq) C6H5COOH (aq) + ClO- (aq)

2) NO2- (aq) + C6H5COOH (aq) HNO2 (aq) + C6H5COO- (aq)

3) HClO (aq) + NO2- (aq) ClO- (aq) + HNO2 (aq)

Arrange the substances based on their relative BASE strength.

C6H5COO-
HClO
C6H5COOH
HNO2
NO2-
ClO-
strongest base
intermediate base
weakest base
not a Bronsted-Lowry base

Answer 1

Ans :- Correct order of basic strength is : ClO^- > C₆H₅COO^- > NO₂^-

Not a Bronsted-Lowry base are : HNO₂ , C₆H₅COOH andHClO

Explanation :-

The following given reactions all have K < 1.

1). C₆H₅COO^- (aq) + HClO (aq) <-------> C₆H₅COOH (aq) + ClO^- (aq)

2). NO₂^- (aq) + C₆H₅COOH (aq) <-------> HNO₂ (aq) + C₆H₅COO^- (aq)

3). HClO (aq) + NO₂^- (aq) <-----------> ClO^- (aq) + HNO₂ (aq)

It is given that , K<1 for all the reactions. It means that reactants are more favor than products i.e. C₆H₅COO^- has less tendency to take H⁺ than ClO^-, therefore ClO^- is stronger base than C₆H₅COO^- (in equation 1).

Similarly, C₆H₅COO^- is strong base than NO₂^- (in equation 2) and ClO^- is stronger base than NO₂^- (in equation 3).

Hence correct order of basic strength is :

ClO^- > C₆H₅COO^- > NO₂^-

Similarly, correct order of acidic strength is :

HNO₂ > C₆H₅COOH> HClO