Question

ACIDS AND BASES - ARRHENIUS, BRONSTED-LOWRY, AND LEWIS 1-27 Briefly explain the three different definitions of acids and bases. 1-28 Calculate the Ka of nitric acid (HNO3). pka of nitric acid is -1.4. 1-29 Rank the following in order of decreasing acidity: NH, HF H,0 H2O 1-30 Rank the following in order of decreasing basicity: HSO4 H2O CH3COO N HY

Answer 1

Question 1-27

3 different definations of acids & based are as follows :

(a) Arrhenius defination of acids & bases -

Acids are those substances that dissociate in water to give hydrogen ions (H⁺) & bases are those substances that dissociate in water to give hydroxyl ions (OH^{​​​​​-}​).

(b) Brönsted-Lowry defination of acids & bases -

Acids are the substances that are able to donate hydrogen ions (H⁺) & bases are the substances that are able to accept hydrogen ions (H⁺)

(c) Lewis theory of acids & bases -

Acids are the substances that accept electron pair & bases are the substances that donate electron pair.

Question 1.28

​​​​​​pKa of nitric acid = -1.4

​​​We've to calculate Ka of nitric acid.

For this, we'll be using formula -

$pK_{a} = -log(K_{a})$

$K_{a} = 10^{-pK_{a}}$

now, putting value to pKa to equation -

$K_{a} = 10^{ -(-1.4)}$

$K_{a} = 10^{1.4}$​​​​​​

$K_{a} = 25.12$.